def absolute_momentum(u_wind, v_wind, index='index'):
r"""Calculate cross-sectional absolute momentum (also called pseudoangular momentum).
As given in [Schultz1999]_, absolute momentum (also called pseudoangular momentum) is
given by
.. math:: M = v + fx
where :math:`v` is the along-front component of the wind and :math:`x` is the cross-front
distance. Applied to a cross-section taken perpendicular to the front, :math:`v` becomes
the normal component of the wind and :math:`x` the tangential distance.
If using this calculation in assessing symmetric instability, geostrophic wind should be
used so that geostrophic absolute momentum :math:`\left(M_g\right)` is obtained, as
described in [Schultz1999]_.
Parameters
----------
u_wind : `xarray.DataArray`
The input DataArray of the x-component (in terms of data projection) of the wind.
v_wind : `xarray.DataArray`
The input DataArray of the y-component (in terms of data projection) of the wind.
Returns
-------
absolute_momentum: `xarray.DataArray`
The absolute momentum
Notes
-----
The coordinates of `u_wind` and `v_wind` must match.
"""
# Get the normal component of the wind
norm_wind = normal_component(u_wind, v_wind, index=index)
norm_wind.metpy.convert_units('m/s')
# Get other pieces of calculation (all as ndarrays matching shape of norm_wind)
latitude = latitude_from_cross_section(norm_wind) # in degrees_north
_, latitude = xr.broadcast(norm_wind, latitude)
f = coriolis_parameter(np.deg2rad(latitude.values)).magnitude # in 1/s
x, y = distances_from_cross_section(norm_wind)
x.metpy.convert_units('meters')
y.metpy.convert_units('meters')
_, x, y = xr.broadcast(norm_wind, x, y)
distance = np.hypot(x, y).values # in meters
m = norm_wind + f * distance
m.attrs = {'units': norm_wind.attrs['units']}
return m
def _get_dates_for_extremes(extr_vals: xarray.DataArray, current_data_chunk: xarray.DataArray,
extr_dates: xarray.DataArray = None):
"""
Helper method to determine the times when the extreme values are occurring
:param extr_vals:
:param current_data_chunk:
:param result_dates:
"""
t3d, _ = xarray.broadcast(current_data_chunk.t, current_data_chunk)
if extr_dates is None:
result_dates = t3d[0, :, :].copy()
else:
result_dates = extr_dates
tis, xis, yis = np.where(extr_vals == current_data_chunk)
npvals = t3d.values
# for ti, xi, yi in zip(tis, xis, yis):
# result_dates[xi, yi] = npvals[ti, xi, yi]
result_dates.values[xis, yis] = npvals[tis, xis, yis]
# debug
return result_dates
def data_for_reg_calcs(values_for_reg_arr):
lat = [-10., 1., 10., 20.]
lon = [1., 10.]
sfc_area = [0.5, 1., 0.5, 0.25]
land_mask = [1., 1., 0., 1.]
lat = xr.DataArray(lat, dims=[LAT_STR], coords=[lat])
lon = xr.DataArray(lon, dims=[LON_STR], coords=[lon])
sfc_area = xr.DataArray(sfc_area, dims=[LAT_STR], coords=[lat])
land_mask = xr.DataArray(land_mask, dims=[LAT_STR], coords=[lat])
sfc_area, _ = xr.broadcast(sfc_area, lon)
land_mask, _ = xr.broadcast(land_mask, lon)
da = xr.DataArray(values_for_reg_arr, coords=[lat, lon])
da.coords[SFC_AREA_STR] = sfc_area
da.coords[LAND_MASK_STR] = land_mask
return da
def test_laplacian_xarray_lonlat(test_da_lonlat):
"""Test laplacian with an xarray.DataArray on a lonlat grid."""
laplac = laplacian(test_da_lonlat, axes=('lat', 'lon'))
# Build the xarray of the desired values
partial = xr.DataArray(
np.array([1.67155420e-14, 1.67155420e-14, 1.74268211e-14, 1.74268211e-14]),
coords=(('lat', test_da_lonlat['lat']),)
)
_, truth = xr.broadcast(test_da_lonlat, partial)
truth.coords['crs'] = test_da_lonlat['crs']
truth.attrs['units'] = 'kelvin / meter^2'
xr.testing.assert_allclose(laplac, truth)
assert laplac.metpy.units == truth.metpy.units
def test_second_derivative_xarray_lonlat(test_da_lonlat):
"""Test second derivative with an xarray.DataArray on a lonlat grid."""
deriv = second_derivative(test_da_lonlat, axis='lat')
# Build the xarray of the desired values
partial = xr.DataArray(
np.array([1.67155420e-14, 1.67155420e-14, 1.74268211e-14, 1.74268211e-14]),
coords=(('lat', test_da_lonlat['lat']),)
)
_, truth = xr.broadcast(test_da_lonlat, partial)
truth.coords['crs'] = test_da_lonlat['crs']
truth.attrs['units'] = 'kelvin / meter^2'
xr.testing.assert_allclose(deriv, truth)
assert deriv.metpy.units == truth.metpy.units
def test_first_derivative_xarray_lonlat(test_da_lonlat):
"""Test first derivative with an xarray.DataArray on a lonlat grid in each axis usage."""
deriv = first_derivative(test_da_lonlat, axis='lon') # dimension coordinate name
deriv_alt1 = first_derivative(test_da_lonlat, axis='x') # axis type
deriv_alt2 = first_derivative(test_da_lonlat, axis=-1) # axis number
# Build the xarray of the desired values
partial = xr.DataArray(
np.array([-3.30782978e-06, -3.42816074e-06, -3.57012948e-06, -3.73759364e-06]),
coords=(('lat', test_da_lonlat['lat']),)
)
_, truth = xr.broadcast(test_da_lonlat, partial)
truth.coords['crs'] = test_da_lonlat['crs']
truth.attrs['units'] = 'kelvin / meter'
# Assert result matches expectation
xr.testing.assert_allclose(deriv, truth)
assert deriv.metpy.units == truth.metpy.units
# Assert alternative specifications give same result
xr.testing.assert_identical(deriv_alt1, deriv)
xr.testing.assert_identical(deriv_alt2, deriv)
def test_gradient_xarray(test_da_xy):
"""Test the 3D gradient calculation with a 4D DataArray in each axis usage."""
deriv_x, deriv_y, deriv_p = gradient(test_da_xy, axes=('x', 'y', 'isobaric'))
deriv_x_alt1, deriv_y_alt1, deriv_p_alt1 = gradient(test_da_xy,
axes=('x', 'y', 'vertical'))
deriv_x_alt2, deriv_y_alt2, deriv_p_alt2 = gradient(test_da_xy, axes=(3, 2, 1))
truth_x = xr.full_like(test_da_xy, -6.993007e-07)
truth_x.attrs['units'] = 'kelvin / meter'
truth_y = xr.full_like(test_da_xy, -2.797203e-06)
truth_y.attrs['units'] = 'kelvin / meter'
partial = xr.DataArray(
np.array([0.04129204, 0.03330003, 0.02264402]),
coords=(('isobaric', test_da_xy['isobaric']),)
)
_, truth_p = xr.broadcast(test_da_xy, partial)
truth_p.coords['crs'] = test_da_xy['crs']
truth_p.attrs['units'] = 'kelvin / hectopascal'
# Assert results match expectations
xr.testing.assert_allclose(deriv_x, truth_x)
assert deriv_x.metpy.units == truth_x.metpy.units
xr.testing.assert_allclose(deriv_y, truth_y)
assert deriv_y.metpy.units == truth_y.metpy.units
xr.testing.assert_allclose(deriv_p, truth_p)
assert deriv_p.metpy.units == truth_p.metpy.units
# Assert alternative specifications give same results
xr.testing.assert_identical(deriv_x_alt1, deriv_x)
xr.testing.assert_identical(deriv_y_alt1, deriv_y)
xr.testing.assert_identical(deriv_p_alt1, deriv_p)
xr.testing.assert_identical(deriv_x_alt2, deriv_x)
xr.testing.assert_identical(deriv_y_alt2, deriv_y)
xr.testing.assert_identical(deriv_p_alt2, deriv_p)
def noisePower(h, p0):
return p0 * h**2
filesW = glob(
'/data/data_hatpro/jue/data/joyrad94/l0/201511/2*/joyrad94_joyce_2015112*.nc'
)
for fw in filesW:
print(fw)
ncfile = xr.open_dataset(fw, drop_variables='velocity')
Ze = ncfile['Ze']
Ze = Ze.where(Ze != -999.0)
Zlin = 10.0**(0.1 * Ze)
t, r = xr.broadcast(Ze.time, Ze.range)
df = pd.DataFrame()
df['Hgt'] = r.data.flatten()
df['Ze'] = Ze.data.flatten()
spec = ncfile.spec
spec = spec.where(spec != -999.0)
speclin = 10.0**(0.1 * spec)
Zg = speclin.sum(dim='velocity', skipna=True)
N = 10.0 * np.log10(Zg - Zlin).data.flatten()
N[~np.isfinite(N)] = np.nan
df['N'] = N
df.dropna(inplace=True, subset=['Ze'])
df.to_hdf('joyrad94snr.h5', key='stat', mode='a', append=True)
print('done')
df = pd.read_hdf('joyrad94snr.h5', key='stat')
def rle(da: xr.DataArray,
dim: str = "time",
max_chunk: int = 1_000_000) -> xr.DataArray:
"""Generate basic run length function.
Parameters
----------
da : xr.DataArray
dim : str
max_chunk : int
Returns
-------
xr.DataArray
Values are 0 where da is False (out of runs),
are N on the first day of a run, where N is the length of that run,
and are NaN on the other days of the runs.
"""
use_dask = isinstance(da.data, dsk.Array)
n = len(da[dim])
# Need to chunk here to ensure the broadcasting is not made in memory
i = xr.DataArray(np.arange(da[dim].size), dims=dim)
if use_dask:
i = i.chunk({dim: -1})
ind, da = xr.broadcast(i, da)
if use_dask:
# Rechunk, but with broadcasted da
ind = ind.chunk(da.chunks)
b = ind.where(~da) # find indexes where false
end1 = (da.where(b[dim] == b[dim][-1], drop=True) * 0 + n
) # add additional end value index (deal with end cases)
start1 = (da.where(b[dim] == b[dim][0], drop=True) * 0 - 1
) # add additional start index (deal with end cases)
b = xr.concat([start1, b, end1], dim)
# Ensure bfill operates on entire (unchunked) time dimension
# Determine appropraite chunk size for other dims - do not exceed 'max_chunk' total size per chunk (default 1000000)
ndims = len(b.shape)
if use_dask:
chunk_dim = b[dim].size
# divide extra dims into equal size
# Note : even if calculated chunksize > dim.size result will have chunk==dim.size
chunksize_ex_dims = None # TODO: This raises type assignment errors in mypy
if ndims > 1:
chunksize_ex_dims = np.round(
np.power(max_chunk / chunk_dim, 1 / (ndims - 1)))
chunks = dict()
chunks[dim] = -1
for dd in b.dims:
if dd != dim:
chunks[dd] = chunksize_ex_dims
b = b.chunk(chunks)
# back fill nans with first position after
z = b.bfill(dim=dim)
# calculate lengths
d = z.diff(dim=dim) - 1
d = d.where(d >= 0)
d = d.isel({dim: slice(None, -1)}).where(da, 0)
return d
def r2(a, b, dim=None, weights=None, skipna=False, keep_attrs=False):
"""R^2 (coefficient of determination) score.
We first take the total sum of squares of our known vector, a.
.. math::
SS_{\\mathrm{tot}} = \\sum_{i=1}^{n} (a_{i} - \\bar{a})^{2}
Next, we take the sum of squares of the error between our known vector
a and the predicted vector, b.
.. math::
SS_{\\mathrm{res}} = \\sum_{i=1}^{n} (a_{i} - b_{i})^{2}
Lastly we compute the coefficient of determiniation using these two
terms.
.. math::
R^{2} = 1 - \\frac{SS_{\\mathrm{res}}}{SS_{\\mathrm{tot}}}
.. note::
The coefficient of determination is *not* symmetric. In other words,
``r2(a, b) != r2(b, a)``. Be careful and note that by our
convention, ``b`` is the modeled/predicted vector and ``a`` is the
observed vector.
Parameters
----------
a : xarray.Dataset or xarray.DataArray
Labeled array(s) over which to apply the function.
b : xarray.Dataset or xarray.DataArray
Labeled array(s) over which to apply the function.
dim : str, list
The dimension(s) to apply the correlation along. Note that this dimension will
be reduced as a result. Defaults to None reducing all dimensions.
weights : xarray.Dataset or xarray.DataArray or None
Weights matching dimensions of ``dim`` to apply during the function.
skipna : bool
If True, skip NaNs when computing function.
keep_attrs : bool
If True, the attributes (attrs) will be copied
from the first input to the new one.
If False (default), the new object will
be returned without attributes.
Returns
-------
xarray.DataArray or xarray.Dataset
R^2 (coefficient of determination) score.
See Also
--------
sklearn.metrics.r2_score
References
----------
https://en.wikipedia.org/wiki/Coefficient_of_determination
Examples
--------
>>> import numpy as np
>>> import xarray as xr
>>> from xskillscore import r2
>>> a = xr.DataArray(np.random.rand(5, 3, 3),
dims=['time', 'x', 'y'])
>>> b = xr.DataArray(np.random.rand(5, 3, 3),
dims=['time', 'x', 'y'])
>>> r2(a, b, dim='time')
"""
_fail_if_dim_empty(dim)
dim, _ = _preprocess_dims(dim, a)
a, b = xr.broadcast(a, b, exclude=dim)
a, b, new_dim, weights = _stack_input_if_needed(a, b, dim, weights)
weights = _preprocess_weights(a, dim, new_dim, weights)
input_core_dims = _determine_input_core_dims(new_dim, weights)
return xr.apply_ufunc(
_r2,
a,
b,
weights,
input_core_dims=input_core_dims,
kwargs={
"axis": -1,
"skipna": skipna
},
dask="parallelized",
output_dtypes=[float],
keep_attrs=keep_attrs,
)
def reproject_xy_to_wgs84(
src_dataset: xr.Dataset,
src_xy_var_names: Tuple[str, str],
src_xy_tp_var_names: Tuple[str, str] = None,
src_xy_crs: str = None,
src_xy_gcp_step: Union[int, Tuple[int, int]] = 10,
src_xy_tp_gcp_step: Union[int, Tuple[int, int]] = 1,
dst_size: Tuple[int, int] = None,
dst_region: CoordRange = None,
dst_resampling: Union[str, Dict[str, str]] = DEFAULT_RESAMPLING,
include_xy_vars: bool = False,
include_non_spatial_vars: bool = False) -> xr.Dataset:
"""
Reprojection of xarray datasets with 2D geo-coding, e.g. with variables lon(y,x), lat(y, x) to
EPSG:4326 (WGS-84) coordinate reference system.
If *dst_resampling* is a string, it provides the default resampling for all variables.
If *dst_resampling* is a dictionary, it provides a mapping from variable names to the desired
resampling for that variable.
The resampling may be one of the following up-sampling algorithms:
* ``Nearest``
* ``Bilinear``
* ``Cubic``
* ``CubicSpline``
* ``Lanczos``
Or one of the down-sampling algorithms:
* ``Average``
* ``Min``
* ``Max``
* ``Median``
* ``Mode``
* ``Q1``
* ``Q3``
:param src_dataset:
:param src_xy_var_names:
:param src_xy_tp_var_names:
:param src_xy_crs:
:param src_xy_gcp_step:
:param src_xy_tp_gcp_step:
:param dst_size:
:param dst_region:
:param dst_resampling: The spatial resampling algorithm. Either a string that provides the default resampling
algorithm name or a dictionary that maps variable names to per-variable resampling algorithm names.
:param include_non_spatial_vars:
:param include_xy_vars: Whether to include the variables given by *src_xy_var_names*.
Useful for projection-validation.
:return: the reprojected dataset
"""
x_name, y_name = src_xy_var_names
tp_x_name, tp_y_name = src_xy_tp_var_names or (None, None)
# Set defaults
src_xy_crs = src_xy_crs or CRS_WKT_EPSG_4326
gcp_i_step, gcp_j_step = (src_xy_gcp_step, src_xy_gcp_step) if isinstance(src_xy_gcp_step, int) \
else src_xy_gcp_step
tp_gcp_i_step, tp_gcp_j_step = (src_xy_tp_gcp_step, src_xy_tp_gcp_step) if src_xy_tp_gcp_step is None or isinstance(
src_xy_tp_gcp_step, int) \
else src_xy_tp_gcp_step
dst_width, dst_height = dst_size
_assert(src_dataset is not None)
_assert(dst_width > 1)
_assert(dst_height > 1)
_assert(gcp_i_step > 0)
_assert(gcp_j_step > 0)
_assert(x_name in src_dataset)
_assert(y_name in src_dataset)
x_var = src_dataset[x_name]
y_var = src_dataset[y_name]
if len(x_var.dims) == 1 and len(y_var.dims) == 1:
y_var, x_var = xr.broadcast(y_var, x_var)
_assert(len(x_var.dims) == 2)
_assert(y_var.dims == x_var.dims)
_assert(x_var.shape[-1] >= 2)
_assert(x_var.shape[-2] >= 2)
_assert(y_var.shape == x_var.shape)
src_width = x_var.shape[-1]
src_height = x_var.shape[-2]
dst_region = _ensure_valid_region(dst_region, GLOBAL_GEO_EXTENT, x_var,
y_var)
dst_x1, dst_y1, dst_x2, dst_y2 = dst_region
dst_res = max((dst_x2 - dst_x1) / dst_width,
(dst_y2 - dst_y1) / dst_height)
_assert(dst_res > 0)
dst_geo_transform = (dst_x1, dst_res, 0.0, dst_y2, 0.0, -dst_res)
# Extract GCPs from full-res lon/lat 2D variables
gcps = _get_gcps(x_var, y_var, gcp_i_step, gcp_j_step)
if tp_x_name and tp_y_name and tp_x_name in src_dataset and tp_y_name in src_dataset:
# If there are tie-point variables in the src_dataset
tp_x_var = src_dataset[tp_x_name]
tp_y_var = src_dataset[tp_y_name]
_assert(len(tp_x_var.shape) == 2)
_assert(tp_x_var.shape == tp_y_var.shape)
tp_width = tp_x_var.shape[-1]
tp_height = tp_x_var.shape[-2]
_assert(tp_gcp_i_step is not None and tp_gcp_i_step > 0)
_assert(tp_gcp_j_step is not None and tp_gcp_j_step > 0)
# Extract GCPs also from tie-point lon/lat 2D variables
tp_gcps = _get_gcps(tp_x_var, tp_y_var, tp_gcp_i_step, tp_gcp_j_step)
else:
# No tie-point variables
tp_x_var = None
tp_width = None
tp_height = None
tp_gcps = None
mem_driver = gdal.GetDriverByName("MEM")
dst_x2 = dst_x1 + dst_res * dst_width
dst_y1 = dst_y2 - dst_res * dst_height
dst_dataset = _new_dst_dataset(dst_width, dst_height, dst_res, dst_x1,
dst_y1, dst_x2, dst_y2)
if dst_resampling is None:
dst_resampling = {}
if isinstance(dst_resampling, str):
dst_resampling = {
var_name: dst_resampling
for var_name in src_dataset.variables
}
for var_name in src_dataset.variables:
src_var = src_dataset[var_name]
if src_var.dims == x_var.dims:
is_tp_var = False
if var_name == x_name or var_name == y_name:
if not include_xy_vars:
# Don't store lat and lon 2D vars in destination
continue
dst_var_name = 'src_' + var_name
else:
dst_var_name = var_name
# PERF: collect variables of same type and size and set band_count accordingly to speed up reprojection
band_count = 1
data_type = numpy_to_gdal_dtype(src_var.dtype)
src_var_dataset = mem_driver.Create(f'src_{var_name}', src_width,
src_height, band_count,
data_type, [])
src_var_dataset.SetGCPs(gcps, src_xy_crs)
elif tp_x_var is not None and src_var.dims == tp_x_var.dims:
is_tp_var = True
if var_name == tp_x_name or var_name == tp_y_name:
if not include_xy_vars:
# Don't store lat and lon 2D vars in destination
continue
dst_var_name = 'src_' + var_name
else:
dst_var_name = var_name
# PERF: collect variables of same type and size and set band_count accordingly to speed up reprojection
band_count = 1
data_type = numpy_to_gdal_dtype(src_var.dtype)
src_var_dataset = mem_driver.Create(f'src_{var_name}', tp_width,
tp_height, band_count,
data_type, [])
src_var_dataset.SetGCPs(tp_gcps, src_xy_crs)
elif include_non_spatial_vars:
# Store any variable as-is, that does not have the lat/lon 2D dims, then continue
dst_dataset[var_name] = src_var
continue
else:
continue
# We use GDT_Float64 to introduce NaN as no-data-value
dst_data_type = gdal.GDT_Float64
dst_var_dataset = mem_driver.Create(f'dst_{var_name}', dst_width,
dst_height, band_count,
dst_data_type, [])
dst_var_dataset.SetProjection(CRS_WKT_EPSG_4326)
dst_var_dataset.SetGeoTransform(dst_geo_transform)
# TODO (forman): PERFORMANCE: stack multiple variables of same src_data_type
# to perform the reprojection only once per stack
# TODO (forman): CODE-DUPLICATION: refactor out common code block in reproject_crs_to_wgs84()
for band_index in range(1, band_count + 1):
src_var_dataset.GetRasterBand(band_index).SetNoDataValue(
float('nan'))
src_var_dataset.GetRasterBand(band_index).WriteArray(
src_var.values)
dst_var_dataset.GetRasterBand(band_index).SetNoDataValue(
float('nan'))
resample_alg, resample_alg_name = _get_resample_alg(
dst_resampling,
var_name,
default=DEFAULT_TP_RESAMPLING if is_tp_var else DEFAULT_RESAMPLING)
warp_mem_limit = 0
error_threshold = 0
# See http://www.gdal.org/structGDALWarpOptions.html
options = ['INIT_DEST=NO_DATA']
gdal.ReprojectImage(
src_var_dataset,
dst_var_dataset,
None,
None,
resample_alg,
warp_mem_limit,
error_threshold,
None, # callback,
None, # callback_data,
options) # options
dst_values = dst_var_dataset.GetRasterBand(1).ReadAsArray()
# print(var_name, dst_values.shape, np.nanmin(dst_values), np.nanmax(dst_values))
dst_dataset[dst_var_name] = _new_dst_variable(src_var, dst_values,
resample_alg_name)
return dst_dataset
def vertical_averaging_weights(self,
time_slice=slice(None),
ztop=None,
zbottom=None,
dz=None,
face_slice=slice(None)):
"""
reimplementation of sunreader.Sunreader::averaging_weights
returns: weights as array [faces,Nk] to average over a cell-centered quantity
for the range specified by ztop,zbottom, and dz.
range is specified by 2 of the 3 of ztop, zbottom, dz, all non-negative.
ztop: dimensional distance from freesurface,
zbottom: dimensional distance from bed
dz: thickness
if the result would be an empty region, return nans.
cell_select: an object which can be used to index into the cell dimension
defaults to all cells.
this thing is slow! - lots of time in adjusting all_dz
order of dimensions has been altered to match local suntans netcdf code,
i.e. face,level,time
"""
mesh = self.nc[self.mesh_name]
face_dim = self.face_dim
if self.face_eta_vname is None:
self.face_eta_vname = self.find_var(
standard_name='sea_surface_height_above_geoid')
assert self.face_eta_vname is not None, "Failed to discern eta variable"
surface = self.face_eta_vname
face_select = {face_dim: face_slice}
h = self.nc[self.face_eta_vname].isel({
self.time_dim: time_slice,
face_dim: face_slice
})
if self.face_depth_vname is None:
self.face_depth_vname = self.find_var(
standard_name=[
"sea_floor_depth_below_geoid", "sea_floor_depth"
],
location='face') # ala 'Mesh_depth'
if self.face_depth_vname is None:
# c'mon people -- should be fixed in source now,
self.face_depth_vname = self.find_var(
stanford_name=[
"sea_floor_depth_below_geoid", "sea_floor_depth"
],
location='face') # ala 'Mesh_depth'
depth = self.face_depth_vname
assert depth is not None, "Failed to find depth variable"
bed = self.nc[depth].isel(**face_select)
if self.nc[depth].attrs.get('positive') == 'down':
log.debug("Cell depth is positive-down")
bed = -bed
else:
log.debug(
"Cell depth is positive-up, or at least that is the assumption"
)
h, bed = xr.broadcast(h, bed)
# for now, can only handle an array of cells - i.e. if you want
# a single face, it's still going to process an array, just with
# length 1.
Ncells = len(bed)
layers = self.nc[self.layer_var_name()]
layer_vals = layers.values
if layers.attrs.get('positive') == 'down':
layer_vals = -layer_vals
if 'bounds' in layers.attrs:
layer_bounds = self.nc[layers.attrs['bounds']].values
# hmm - some discrepancies over the dimensionality of layer_interfaces
# assumption is probably that the dimensions are [layer,{top,bottom}]
if layer_bounds.ndim == 2 and layer_bounds.shape[1] == 2:
# same layer interfaces for all cells, all time.
layer_interfaces = np.concatenate(
(layer_bounds[:, 0], layer_bounds[-1:, 1]))
if layers.attrs.get('positive') == 'down':
layer_interfaces = -layer_interfaces
else:
raise Exception(
"Not smart enough about layer_bounds to do this")
else:
dz_single = 0 - bed.values.min(
) # assumes typ eta of 0. only matters for 2D
layer_interfaces = utils.center_to_edge(layer_vals,
dx_single=dz_single)
layer_bounds = np.concatenate(
(layer_interfaces[:-1, None], layer_interfaces[1:, None]),
axis=1)
# used to retain layer_interfaces for the top of the top and the
# bottom of the bottom. But that just makes for more cleanup
# so now clip this to be interfaces between two layers.
layer_interfaces = layer_interfaces[1:-1]
# Calls to searchsorted below may need to negate both arguments
# if increasing k maps to decreasing elevation.
if np.all(np.diff(layer_interfaces) < 0):
k_sign = -1
elif np.all(np.diff(layer_interfaces) > 0):
k_sign = 1
else:
raise Exception("Confused about the ordering of k")
# this is a bit trickier, because there could be lumping. for now, it should work okay
# with 2-d, but won't be good for 3-d HERE if k is increasing up, this is WRONG
# this used to be called Nk, but that's misleading. it's the k index
# of the bed layer, not the number of layers per water column.
kbed = np.searchsorted(k_sign * layer_interfaces, k_sign * bed)
one_dz = k_sign * (layer_bounds[:, 1] - layer_bounds[:, 0])
all_dz = np.ones(h.shape + one_dz.shape) * one_dz
all_k = np.ones(h.shape + one_dz.shape, np.int32) * np.arange(
len(one_dz))
# adjust bed and
# 3 choices here..
# try to clip to reasonable values at the same time:
if ztop is not None:
if ztop != 0:
h = h - ztop # don't modify h
# don't allow h to go below the bed
h[h < bed] = bed[h < bed]
if dz is not None:
# don't allow bed to be below the real bed.
bed = np.maximum(h - dz, bed)
if zbottom is not None:
# no clipping checks for zbottom yet.
if zbottom != 0:
bed = bed + zbottom # don't modify bed!
if dz is not None:
h = bed + dz
# so now h and bed are elevations bounding the integration region
# with this min call it's only correct for k_sign==-1
ctops = np.searchsorted(
k_sign * (layer_interfaces + self.surface_dzmin), k_sign * h)
# default h_to_ctop will use the dzmin appropriate for the surface,
# but at the bed, it goes the other way - safest just to say dzmin=0,
# and also clamp to known Nk
cbeds = np.searchsorted(k_sign * layer_interfaces, k_sign * bed)
# dimension problems here - Nk has dimensions like face_slice or face_slice,time_slice
# cbeds has dimensions like face_slice,time_slice
# how to conditionally add dimensions to Nk?
# for now, ASSUME that time is after face, and use shape of h to
# figure out how to pad it
while h.ndim > kbed.ndim:
kbed = kbed[..., None]
# also have to expand Nk so that the boolean indexing works
# use to make cbeds exclusive indexing, but its cleaner to leave
# ctops and cbeds both as inclusive, since it changes based on
# k_sign
if k_sign == -1:
# keep cbed valid w.r.t. to deepest layer kbed,
cbeds = np.minimum(cbeds, kbed)
drymask = (all_k < ctops[..., None]) | (all_k > cbeds[..., None])
else:
cbeds = np.maximum(cbeds, kbed) # maybe redundant now
drymask = (all_k < cbeds[..., None]) | (all_k > ctops[..., None])
all_dz[drymask] = 0.0
ii = tuple(np.indices(h.shape))
z = layer_bounds.min(axis=1) # bottom of each cell
all_dz[ii + (ctops[ii], )] = h - z[ctops]
all_dz[ii + (cbeds[ii], )] -= bed - z[cbeds]
# make those weighted averages
# have to add extra axis to get broadcasting correct
all_dz = all_dz / np.sum(all_dz, axis=-1)[..., None]
if all_dz.ndim == 3:
# we have both time and level
# transpose to match the shape of velocity data -
all_dz = all_dz.transpose([0, 2, 1])
return all_dz
def median_absolute_error(a, b, dim=None, skipna=False, keep_attrs=False):
"""
Median Absolute Error.
.. math::
\\mathrm{median}(\\vert a - b\\vert)
Parameters
----------
a : xarray.Dataset or xarray.DataArray
Labeled array(s) over which to apply the function.
b : xarray.Dataset or xarray.DataArray
Labeled array(s) over which to apply the function.
dim : str, list
The dimension(s) to apply the median absolute error along.
Note that this dimension will be reduced as a result.
Defaults to None reducing all dimensions.
skipna : bool
If True, skip NaNs when computing function.
keep_attrs : bool
If True, the attributes (attrs) will be copied
from the first input to the new one.
If False (default), the new object will
be returned without attributes.
Returns
-------
xarray.Dataset or xarray.DataArray
Median Absolute Error.
See Also
--------
sklearn.metrics.median_absolute_error
Examples
--------
>>> import numpy as np
>>> import xarray as xr
>>> from xskillscore import median_absolute_error
>>> a = xr.DataArray(np.random.rand(5, 3, 3),
dims=['time', 'x', 'y'])
>>> b = xr.DataArray(np.random.rand(5, 3, 3),
dims=['time', 'x', 'y'])
>>> median_absolute_error(a, b, dim='time')
"""
dim, axis = _preprocess_dims(dim, a)
a, b = xr.broadcast(a, b, exclude=dim)
return xr.apply_ufunc(
_median_absolute_error,
a,
b,
input_core_dims=[dim, dim],
kwargs={
"axis": axis,
"skipna": skipna
},
dask="parallelized",
output_dtypes=[float],
keep_attrs=keep_attrs,
)
dx=median_dx
if dz is None:
all_dz=[ np.abs(get_z_dz(tran).values.ravel())
for tran in trans]
all_dz=np.concatenate( all_dz )
# generally want to retain most of the vertical
# resolution, but not minimum dz since there could be
# some partial layers, near-field layers, etc.
# even 10th percentile may be small.
dz=np.percentile(all_dz,10)
# Get the maximum range of valid vertical
z_bnds=[]
for tran in trans:
V,z_full,z_dz = xr.broadcast(tran.Ve, tran.z_ctr, get_z_dz(tran))
valid=np.isfinite(V.values)
z_valid=z_full.values[valid]
z_low=z_full.values[valid] - z_dz.values[valid]/2.0
z_high=z_full.values[valid] + z_dz.values[valid]/2.0
z_bnds.append( [z_low.min(), z_high.max()] )
z_bnds=np.concatenate(z_bnds)
z_min=z_bnds.min()
z_max=z_bnds.max()
# Resample each transect in the vertical:
new_z=np.linspace(z_min,z_max,int(round((z_max-z_min)/dz)))
##
start = (37.0, -105.0)
end = (35.5, -65.0)
##############################
# Get the cross section, and convert lat/lon to supplementary coordinates:
cross = cross_section(data, start, end)
cross.set_coords(('lat', 'lon'), True)
print(cross)
##############################
# For this example, we will be plotting potential temperature, relative humidity, and
# tangential/normal winds. And so, we need to calculate those, and add them to the dataset:
temperature, pressure, specific_humidity = xr.broadcast(
cross['Temperature'], cross['isobaric'], cross['Specific_humidity'])
theta = mpcalc.potential_temperature(pressure, temperature)
rh = mpcalc.relative_humidity_from_specific_humidity(specific_humidity,
temperature, pressure)
# These calculations return unit arrays, so put those back into DataArrays in our Dataset
cross['Potential_temperature'] = xr.DataArray(theta,
coords=temperature.coords,
dims=temperature.dims,
attrs={'units': theta.units})
cross['Relative_humidity'] = xr.DataArray(rh,
coords=specific_humidity.coords,
dims=specific_humidity.dims,
attrs={'units': rh.units})
def _apply_metric_at_given_lead(
verif,
verif_dates,
lead,
hind=None,
hist=None,
inits=None,
reference=None,
metric=None,
comparison=None,
dim=None,
**metric_kwargs,
):
"""Applies a metric between two time series at a given lead.
.. note::
This will be moved to a method of the `Scoring()` class in the next PR.
Args:
verif (xr object): Verification data.
verif_dates (dict): Lead-dependent verification dates for alignment.
lead (int): Given lead to score.
hind (xr object): Initialized hindcast. Not required in a persistence forecast.
hist (xr object): Historical simulation. Required when
``reference='historical'``.
inits (dict): Lead-dependent initialization dates for alignment.
reference (str): If not ``None``, return score for this reference forecast.
* 'persistence'
* 'historical'
metric (Metric): Metric class for scoring.
comparison (Comparison): Comparison class.
dim (str): Dimension to apply metric over.
Returns:
result (xr object): Metric results for the given lead for the initialized
forecast or reference forecast.
"""
if reference is None:
# Use `.where()` instead of `.sel()` to account for resampled inits when
# bootstrapping.
a = (hind.sel(lead=lead).where(hind['time'].isin(inits[lead]),
drop=True).drop_vars('lead'))
b = verif.sel(time=verif_dates[lead])
elif reference == 'persistence':
a, b = persistence(verif, inits, verif_dates, lead)
elif reference == 'historical':
a, b = historical(hist, verif, verif_dates, lead)
a['time'] = b['time']
# broadcast dims when deterministic metric and apply over member
if (a.dims != b.dims) and (dim == 'member') and not metric.probabilistic:
a, b = xr.broadcast(a, b)
result = metric.function(
a,
b,
dim=dim,
comparison=comparison,
**metric_kwargs,
)
log_compute_hindcast_inits_and_verifs(dim, lead, inits, verif_dates)
return result
def lateral_fill(da_in, isvalid_mask, ltripole=False, tol=1.0e-4,
use_sor=False, rc=1.8, max_iter=1000):
"""Perform lateral fill on xarray.DataArray
Parameters
----------
da_in : xarray.DataArray
DataArray on which to fill NaNs. Fill is performed on the two
rightmost dimenions. Grid is assumed periodic in `x` direction
(last dimension).
isvalid_mask : xarray.DataArray, boolean
Valid values mask: `True` where data should be filled. Must have the
same rightmost dimenions as `da_in`.
ltripole : boolean, optional [default=False]
Logical flag; if `True` then treat the top row of the grid as periodic
in the sense of a tripole grid.
tol : float, optional [default=1.0e-4]
Convergence criteria: stop filling when values change is less or equal
to `tol * var`; i.e. `delta <= tol * np.abs(var[j, i])`.
use_sor: boolean, optional [default=False]
switch to select SOR fill algorithm over progressive fill algorithm
rc : float, optional [default=1.8, valid bounds=(1.0,2.0)]
over-relaxation coefficient to use in SOR fill algorithm. Larger arrrays
typically converge faster with larger coefficients. For 1 deg. grid (360x180)
a coefficient in the range 1.85-1.9 is near optimal.
max_iter : integer, optional, [default=1000]
maximum number of iterations to do before giving up if tol is not reached.
Returns
-------
da_out : xarray.DataArray
DataArray with NaNs filled by iterative smoothing.
"""
print("IN FOB version : lateral_fill")
dims_in = da_in.dims
non_lateral_dims = dims_in[:-2]
attrs = da_in.attrs
encoding = da_in.encoding
coords = da_in.coords
da_in, isvalid_mask = xr.broadcast(da_in, isvalid_mask)
if len(non_lateral_dims) > 0:
da_in_stack = da_in.stack(non_lateral_dims=non_lateral_dims)
da_out_stack = xr.full_like(da_in_stack, fill_value=np.nan)
isvalid_mask_stack = isvalid_mask.stack(non_lateral_dims=non_lateral_dims)
for i in range(da_in_stack.shape[-1]):
arr = da_in_stack.data[:, :, i]
da_out_stack[:, :, i] = lateral_fill_np_array(arr, isvalid_mask_stack.data[:, :, i],
ltripole,tol,use_sor,rc,max_iter)
da_out = da_out_stack.unstack('non_lateral_dims').transpose(*dims_in)
else:
da_out = xr.full_like(da_in, fill_value=np.nan)
da_out[:, :] = lateral_fill_np_array(da_in.data, isvalid_mask.data,
ltripole,tol,use_sor,rc,max_iter)
da_out.attrs = attrs
da_out.encoding = encoding
for k, da in coords.items():
da_out[k].attrs = da.attrs
return da_out
def compute_perfect_model(
init_pm,
control,
metric='pearson_r',
comparison='m2e',
dim=None,
add_attrs=True,
**metric_kwargs,
):
"""
Compute a predictability skill score for a perfect-model framework
simulation dataset.
Args:
init_pm (xarray object): ensemble with dims ``lead``, ``init``, ``member``.
control (xarray object): control with dimension ``time``.
metric (str): `metric` name, see
:py:func:`climpred.utils.get_metric_class` and (see :ref:`Metrics`).
comparison (str): `comparison` name defines what to take as forecast
and verification (see
:py:func:`climpred.utils.get_comparison_class` and :ref:`Comparisons`).
dim (str or list): dimension to apply metric over. default: ['member', 'init']
add_attrs (bool): write climpred compute args to attrs. default: True
** metric_kwargs (dict): additional keywords to be passed to metric.
(see the arguments required for a given metric in metrics.py)
Returns:
skill (xarray object): skill score with dimensions as input `ds`
without `dim`.
"""
# Check that init is int, cftime, or datetime; convert ints or cftime to datetime.
init_pm = convert_time_index(init_pm,
'init',
'init_pm[init]',
calendar=PM_CALENDAR_STR)
# check args compatible with each other
metric, comparison, dim = _get_metric_comparison_dim(metric,
comparison,
dim,
kind='PM')
forecast, verif = comparison.function(init_pm, metric=metric)
# in case you want to compute deterministic skill over member dim
if (forecast.dims != verif.dims) and not metric.probabilistic:
forecast, verif = xr.broadcast(forecast, verif)
skill = metric.function(forecast,
verif,
dim=dim,
comparison=comparison,
**metric_kwargs)
if comparison.name == 'm2m':
skill = skill.mean(M2M_MEMBER_DIM)
# Attach climpred compute information to skill
if add_attrs:
skill = assign_attrs(
skill,
init_pm,
function_name=inspect.stack()[0][3],
metric=metric,
comparison=comparison,
dim=dim,
metadata_dict=metric_kwargs,
)
return skill
def truncate_dataarray(dataarray,
quantile_dims,
replace_with_mean=False,
mean_dims=None,
weights=None,
quantiles=None,
extra_dim=None):
r"""Truncates the dataarray over the given dimensions, meaning that data
outside the upper and lower quantiles, which are taken across the
dimensions ``quantile_dims``, are replaced either with:
1. the upper and lower quantiles themselves.
2. or with the mean of the in-lier data, which is taken across the
dimensions given by ``mean_dims``.
**Note**: If weights are given, then weighted-quantiles and weighted-means
are taken, otherwise the quantiles and means are unweighted.
Args:
dataarray (xarray.DataArray):
dataarray that has at least the dimensions given by ``dims``, and
if ``replace_with_mean`` is True, then also ``mean_dims``.
replace_with_mean (bool, optional):
If True, then replace values outside of the upper and lower
quantiles and with the mean across the dimensions given by
`mean_dims`, if False, then replace with the upper and lower bounds
themselves.
mean_dims (list[str], optional):
dimensions to take mean within the bounds over
quantile_dims (list[str]):
dimensions to take quantiles over -- the quantiles are
used to make the bounds.
weights (xarray.DataArray, optional):
Must have one dimension and can have up two dimensions.
quantiles (tuple[float, float] | list[float, float], optional):
The tuple of two floats representing the quantiles to take.
extra_dim (str):
Extra dimension that exists in `weights` and `data`. It should not
be in `stat_dims`.
Returns:
(xarray.DataArray):
Same shape as the original array, but with truncated values.
Raises:
(ValueError):
If `replace_with_mean` is True, and `mean_dims` is not list of
strings.
"""
LOGGER.debug("Entering the `truncate_dataarray` function")
LOGGER.debug("quantile_dims:{}".format(quantile_dims))
LOGGER.debug("replace_with_mean:{}".format(replace_with_mean))
LOGGER.debug("mean_dims:{}".format(mean_dims))
LOGGER.debug("weights:{}".format(weights))
LOGGER.debug("quantiles:{}".format(quantiles))
LOGGER.debug("extra_dim:{}".format(extra_dim))
if replace_with_mean and not mean_dims:
mean_dims_err_msg = (
"If `replace_with_mean` is True, then `mean_dims` "
"must be a list of strings")
LOGGER.error(mean_dims_err_msg)
raise ValueError(mean_dims_err_msg)
else:
pass # `mean_dims` doesn't can be None
quantiles = (Quantiles(
*sorted(quantiles)) if quantiles else Quantiles(0.05, 0.95))
if weights is not None:
quantile_values = weighted_quantile_with_extra_dim(
dataarray, quantiles, list(quantile_dims), weights, extra_dim)
else:
quantile_values = dataarray.quantile(quantiles,
dim=list(quantile_dims))
lower_da = quantile_values.sel(quantile=quantiles.lower)
upper_da = quantile_values.sel(quantile=quantiles.upper)
if replace_with_mean:
good_indexes = (dataarray >= lower_da) & (dataarray <= upper_da)
inside_da = dataarray.where(good_indexes)
outside_da = dataarray.where(~good_indexes)
if weights is not None:
inside_mean_da = weighted_mean_with_extra_dim(
inside_da, mean_dims, weights, extra_dim)
else:
inside_mean_da = inside_da.mean(mean_dims)
truncated_da = (inside_da.combine_first(
xr.ones_like(outside_da) * inside_mean_da))
else:
expanded_lower_da, _ = xr.broadcast(lower_da, dataarray)
expanded_lower_da = expanded_lower_da.transpose(*dataarray.coords.dims)
expanded_upper_da, _ = xr.broadcast(upper_da, dataarray)
expanded_upper_da = expanded_upper_da.transpose(*dataarray.coords.dims)
truncated_da = dataarray.clip(min=expanded_lower_da,
max=expanded_upper_da)
LOGGER.debug("Leaving the `truncate_dataarray` function")
return truncated_da
) * 100
# assign back to the dataframe
df_window.loc[sinds, 'PNI'] = y[f'{var_col}{rolling_window}'].values
# -----------------------------------------------------------------------------
## calculate Percent of Normal Index (PNI)
# -----------------------------------------------------------------------------
# -----------------------------------------------------------------------------
## Trying to test the broadcast functionality
# -----------------------------------------------------------------------------
xr.broadcast(c_window, mthly_climatology)
# ASSIGN DIMENSION to xarray object
min_yr = 2010
max_yr = 2015
n_yrs = max_yr - min_yr + 1
da = xr.DataArray(
c_window['time.month'].values,
coords=[('month', np.tile(np.arange(1, 13), n_yrs))]
)
c_window, _ = xr.broadcast(c_window, da)
# apply to each month (easier to )
mth = 1
c_window.sel(month=mth)
import read_sontek ## six.moves.reload_module(read_sontek) rivr_fn='040518_7_BTref/20180405125420r.rivr' ds=read_sontek.surveyor_to_xr(rivr_fn,proj='EPSG:26910') ## # Transect of speed plt.figure(1).clf() fig,ax=plt.subplots(num=1) x,z,speed = xr.broadcast(ds.track_dist,-ds.location,ds.water_speed) scat=ax.scatter(x, z, 40, speed, cmap='jet') plt.colorbar(scat) ## # Plan view, scatter and quiver plt.figure(2).clf() fig,ax=plt.subplots(num=2) scat=ax.scatter(ds.x_utm, ds.y_utm, 40, ds.mean_water_speed, cmap='jet') avg_east=ds.Ve.mean(dim='cell') avg_north=ds.Vn.mean(dim='cell') quiv=ax.quiver(ds.x_utm.values, ds.y_utm.values, avg_east.values, avg_north.values) plt.colorbar(scat,label='Speed m/s')
def sinusoidal(self):
moreval = 1
step = 0.1
# Horizontal Dimensions
X = xr.DataArray( np.arange(self.NX*moreval), dims = 'X') * step
Xp1 = xr.DataArray( np.arange(self.NX*moreval+1)-0.5, dims = 'Xp1')* step
Y = xr.DataArray( np.arange(self.NY*moreval), dims = 'Y') * step
Yp1 = xr.DataArray( np.arange(self.NY*moreval+1)-0.5, dims = 'Yp1')* step
# Vertical Dimensions
Z = xr.DataArray(-np.arange(self.NZ*moreval)-0.5, dims = 'Z') * step
Zp1 = xr.DataArray(-np.arange(self.NZ*moreval+1), dims = 'Zp1')* step
Zu = xr.DataArray(-np.arange(self.NZ*moreval)-1, dims = 'Zu') * step
Zl = xr.DataArray(-np.arange(self.NZ*moreval), dims = 'Zl') * step
# Space Coordinates
YC, XC = xr.broadcast(Y, X)
YG, XG = xr.broadcast(Yp1, Xp1)
YU, XU = xr.broadcast(Y , Xp1)
YV, XV = xr.broadcast(Yp1, X)
# Spacing
drC = xr.full_like(Zp1, step)
drF = xr.full_like(Z , step)
dxC = xr.full_like(XU, step)
dyC = xr.full_like(XV, step)
dxF = xr.full_like(XC, step)
dyF = xr.full_like(XC, step)
dxG = xr.full_like(XV, step)
dyG = xr.full_like(XU, step)
dxV = xr.full_like(XG, step)
dyU = xr.full_like(XG, step)
# Areas
rA = dxF * dyF
rAw = dxC * dyG
rAs = dxG * dyC
rAz = dxV * dyU
# HFac
HFacC, _ = xr.broadcast(xr.full_like(Z, 1), xr.full_like(XC, 1))
HFacW, _ = xr.broadcast(xr.full_like(Z, 1), xr.full_like(XU, 1))
HFacS, _ = xr.broadcast(xr.full_like(Z, 1), xr.full_like(XV, 1))
# Sin C points
sinZ, sinY, sinX = xr.broadcast(np.sin(Z), np.sin(Y), np.sin(X))
# Sin vel points
sinUZ, sinUY , sinUX = xr.broadcast(np.sin(Z) , np.sin(Y) , np.sin(Xp1))
sinVZ, sinVY , sinVX = xr.broadcast(np.sin(Z) , np.sin(Yp1), np.sin(X))
sinWZ, sinWY , sinWX = xr.broadcast(np.sin(Zl), np.sin(Y) , np.sin(X))
return xr.Dataset({'X' : X, 'Xp1' : Xp1,
'Y' : Y, 'Yp1' : Yp1,
'Z' : Z, 'Zp1' : Zp1, 'Zu': Zu, 'Zl': Zl,
'YC' : YC, 'XC' : XC,
'YG' : YG, 'XG' : XG,
'YU' : YU, 'XU' : XU,
'YV' : YV, 'XV' : XV,
'drC' : drC, 'drF' : drF,
'dxC' : dxC, 'dyC' : dyC,
'dxF' : dxF, 'dyF' : dyF,
'dxG' : dxG, 'dyG' : dyG,
'dxV' : dxV, 'dyU' : dyU,
'rA' : rA, 'rAw' : rAw,
'rAs' : rAs, 'rAz' : rAz,
'HFacC' : HFacC, 'HFacW' : HFacW, 'HFacS' : HFacS,
'sinZ' : sinZ, 'sinY' : sinY, 'sinX' : sinX,
'sinUZ' : sinUZ, 'sinUY' : sinUY, 'sinUX' : sinUX,
'sinVZ' : sinVZ, 'sinVY' : sinVY, 'sinVX' : sinVX,
'sinWZ' : sinWZ, 'sinWY' : sinWY, 'sinWX' : sinWX})
def getProfileAllBroadcasted(self, variables=None, sel={}):
if variables is None:
return xr.broadcast(self.profile.sel(**sel))[0]
else:
return xr.broadcast(self.profile.sel(**sel)[variables])[0]
# Cross section along 69.3 latitude and between 1 and 25 longitude
# Andenes = 16deg longitude
start = (69.3, 1)
end = (69.3, 25)
cross_data = data[[
'cloud_area_fraction_pl', 'air_temperature_pl', 'relative_humidity_pl'
]]
cross = cross_section(cross_data, start, end).set_coords(
('latitude', 'longitude'))
# Inverse the pressure axes (doesn't work as intended)
# cross = cross.reindex(pressure=list(reversed(cross.pressure)))
temperature, clouds, relative_humidity = xr.broadcast(
cross['air_temperature_pl'], cross['cloud_area_fraction_pl'],
cross['relative_humidity_pl'])
# Plot the cross section
fig, axs = plt.subplots(nrows=3,
ncols=3,
sharey=True,
sharex=True,
figsize=(14, 10))
ax = axs.ravel().tolist()
j = 0
# Define the figure object and primary axes
for i in [0, 6, 12, 18, 24, 30, 36, 42, 48]:
# Plot RH using contourf
rh_contour = ax[j].contourf(cross['longitude'],
def calc_com_incline_and_orientation_angle(da_mask,
return_centerline_pts=False):
"""
Calculate approximate shear angle of object (theta) and xy-orientation
angle (phi) from the change of xy-position of the center-of-mass computed
separately at every height
"""
if np.any(da_mask.isnull()):
m = ~da_mask.isnull()
else:
m = da_mask
# need to center coordinates on "center of mass" (assuming constant density)
if len(da_mask.x.shape) == 3:
x_3d = da_mask.x
y_3d = da_mask.y
z_3d = da_mask.z
else:
x_3d, y_3d, z_3d = xr.broadcast(da_mask.x, da_mask.y, da_mask.z)
# compute mean xy-position at every height z, this is the effective
# centre-of-mass
kws = dict(dtype='float64', dim=('x', 'y'))
x_c = x_3d.where(m).mean(
**kws) # other=nan so that these get excluded from mean calculation
y_c = y_3d.where(m).mean(**kws)
try:
dx = np.gradient(x_c)
dy = np.gradient(y_c)
dx_mean = np.nanmean(dx)
dy_mean = np.nanmean(dy)
dl_mean = np.sqrt(dx_mean**2. + dy_mean**2.)
dz_mean = np.nanmean(np.gradient(x_c.z))
theta = np.arctan2(dl_mean, dz_mean)
phi = np.arctan2(dy_mean, dx_mean)
except ValueError:
phi = theta = np.nan
phi = np.rad2deg(phi)
theta = np.rad2deg(theta)
if phi < 0:
phi += 360.
ds = xr.merge([
xr.DataArray(phi,
name='phi',
attrs=dict(long_name='xy-plane angle', units='deg')),
xr.DataArray(theta,
name='theta',
attrs=dict(long_name='z-axis slope angle', units='deg')),
])
if return_centerline_pts:
return ds, [x_c, y_c, da_mask.z]
else:
return ds
z = -tran_dss[0].depth_bt
else:
# for untrim output:
z = -(tran_dss[0].z_surf - tran_dss[0].z_bed)
zmax = 0.0
zmin = z.min() - 0.2
xmin = x_lat.min() - 3.0
xmax = x_lat.max() + 3.0
for repeat, ds in enumerate(tran_dss):
ds_lateral = ds_to_linear(ds)
Vlong = ds.Ve * along_unit[0] + ds.Vn * along_unit[1]
Vlat = ds.Ve * across_unit[0] + ds.Vn * across_unit[1]
X, Z = xr.broadcast(ds_lateral, ds.z_ctr)
fig = plt.figure(4)
fig.clf()
fig.set_size_inches((10, 6), forward=True)
fig, (ax_lon, ax_lat) = plt.subplots(2,
1,
num=4,
sharex=True,
sharey=True)
scat_lon = ax_lon.scatter(X,
Z,
30,
Vlong,
cmap='jet',
def bootstrap_compute(
hind,
verif,
hist=None,
alignment="same_verifs",
metric="pearson_r",
comparison="m2e",
dim="init",
reference=None,
resample_dim="member",
sig=95,
iterations=500,
pers_sig=None,
compute=compute_hindcast,
resample_uninit=bootstrap_uninitialized_ensemble,
**metric_kwargs,
):
"""Bootstrap compute with replacement.
Args:
hind (xr.Dataset): prediction ensemble.
verif (xr.Dataset): Verification data.
hist (xr.Dataset): historical/uninitialized simulation.
metric (str): `metric`. Defaults to 'pearson_r'.
comparison (str): `comparison`. Defaults to 'm2e'.
dim (str or list): dimension(s) to apply metric over. default: 'init'.
reference (str, list of str): Type of reference forecasts with which to
verify. One or more of ['persistence', 'uninitialized'].
If None or empty, returns no p value.
resample_dim (str): dimension to resample from. default: 'member'::
- 'member': select a different set of members from hind
- 'init': select a different set of initializations from hind
sig (int): Significance level for uninitialized and
initialized skill. Defaults to 95.
pers_sig (int): Significance level for persistence skill confidence levels.
Defaults to sig.
iterations (int): number of resampling iterations (bootstrap
with replacement). Defaults to 500.
compute (func): function to compute skill.
Choose from
[:py:func:`climpred.prediction.compute_perfect_model`,
:py:func:`climpred.prediction.compute_hindcast`].
resample_uninit (func): function to create an uninitialized ensemble
from a control simulation or uninitialized large
ensemble. Choose from:
[:py:func:`bootstrap_uninitialized_ensemble`,
:py:func:`bootstrap_uninit_pm_ensemble_from_control`].
** metric_kwargs (dict): additional keywords to be passed to metric
(see the arguments required for a given metric in :ref:`Metrics`).
Returns:
results: (xr.Dataset): bootstrapped results for the three different skills:
- `initialized` for the initialized hindcast `hind` and describes skill due
to initialization and external forcing
- `uninitialized` for the uninitialized/historical and approximates skill
from external forcing
- `persistence` for the persistence forecast computed by
`compute_persistence`
the different results:
- `verify skill`: skill values
- `p`: p value
- `low_ci` and `high_ci`: high and low ends of confidence intervals based
on significance threshold `sig`
Reference:
* Goddard, L., A. Kumar, A. Solomon, D. Smith, G. Boer, P.
Gonzalez, V. Kharin, et al. “A Verification Framework for
Interannual-to-Decadal Predictions Experiments.” Climate
Dynamics 40, no. 1–2 (January 1, 2013): 245–72.
https://doi.org/10/f4jjvf.
See also:
* climpred.bootstrap.bootstrap_hindcast
* climpred.bootstrap.bootstrap_perfect_model
"""
warn_if_chunking_would_increase_performance(hind, crit_size_in_MB=5)
if pers_sig is None:
pers_sig = sig
if isinstance(dim, str):
dim = [dim]
if isinstance(reference, str):
reference = [reference]
if reference is None:
reference = []
p = (100 - sig) / 100
ci_low = p / 2
ci_high = 1 - p / 2
p_pers = (100 - pers_sig) / 100
ci_low_pers = p_pers / 2
ci_high_pers = 1 - p_pers / 2
# get metric/comparison function name, not the alias
metric = METRIC_ALIASES.get(metric, metric)
comparison = COMPARISON_ALIASES.get(comparison, comparison)
# get class Metric(metric)
metric = get_metric_class(metric, ALL_METRICS)
# get comparison function
comparison = get_comparison_class(comparison, ALL_COMPARISONS)
# Perfect Model requires `same_inits` setup
isHindcast = True if comparison.name in HINDCAST_COMPARISONS else False
reference_alignment = alignment if isHindcast else "same_inits"
chunking_dims = [d for d in hind.dims if d not in CLIMPRED_DIMS]
# carry alignment for compute_reference separately
metric_kwargs_reference = metric_kwargs.copy()
metric_kwargs_reference["alignment"] = reference_alignment
# carry alignment in metric_kwargs
if isHindcast:
metric_kwargs["alignment"] = alignment
if hist is None: # PM path, use verif = control
hist = verif
# slower path for hindcast and resample_dim init
if resample_dim == "init" and isHindcast:
warnings.warn("resample_dim=`init` will be slower than resample_dim=`member`.")
(
bootstrapped_init_skill,
bootstrapped_uninit_skill,
bootstrapped_pers_skill,
) = _bootstrap_hindcast_over_init_dim(
hind,
hist,
verif,
dim,
reference,
resample_dim,
iterations,
metric,
comparison,
compute,
resample_uninit,
**metric_kwargs,
)
else: # faster: first _resample_iterations_idx, then compute skill
resample_func = _get_resample_func(hind)
if not isHindcast:
if "uninitialized" in reference:
# create more members than needed in PM to make the uninitialized
# distribution more robust
members_to_sample_from = 50
repeat = members_to_sample_from // hind.member.size + 1
uninit_hind = xr.concat(
[resample_uninit(hind, hist) for i in range(repeat)],
dim="member",
**CONCAT_KWARGS,
)
uninit_hind["member"] = np.arange(1, 1 + uninit_hind.member.size)
if dask.is_dask_collection(uninit_hind):
# too minimize tasks: ensure uninit_hind get pre-computed
# alternativly .chunk({'member':-1})
uninit_hind = uninit_hind.compute().chunk()
# resample uninit always over member and select only hind.member.size
bootstrapped_uninit = resample_func(
uninit_hind,
iterations,
"member",
replace=False,
dim_max=hind["member"].size,
)
bootstrapped_uninit["lead"] = hind["lead"]
# effectively only when _resample_iteration_idx which doesnt use dim_max
bootstrapped_uninit = bootstrapped_uninit.isel(
member=slice(None, hind.member.size)
)
bootstrapped_uninit["member"] = np.arange(
1, 1 + bootstrapped_uninit.member.size
)
if dask.is_dask_collection(bootstrapped_uninit):
bootstrapped_uninit = bootstrapped_uninit.chunk({"member": -1})
bootstrapped_uninit = _maybe_auto_chunk(
bootstrapped_uninit, ["iteration"] + chunking_dims
)
else: # hindcast
if "uninitialized" in reference:
uninit_hind = resample_uninit(hind, hist)
if dask.is_dask_collection(uninit_hind):
# too minimize tasks: ensure uninit_hind get pre-computed
# maybe not needed
uninit_hind = uninit_hind.compute().chunk()
bootstrapped_uninit = resample_func(
uninit_hind, iterations, resample_dim
)
bootstrapped_uninit = bootstrapped_uninit.isel(
member=slice(None, hind.member.size)
)
bootstrapped_uninit["lead"] = hind["lead"]
if dask.is_dask_collection(bootstrapped_uninit):
bootstrapped_uninit = _maybe_auto_chunk(
bootstrapped_uninit.chunk({"lead": 1}),
["iteration"] + chunking_dims,
)
if "uninitialized" in reference:
bootstrapped_uninit_skill = compute(
bootstrapped_uninit,
verif,
metric=metric,
comparison="m2o" if isHindcast else comparison,
dim=dim,
add_attrs=False,
**metric_kwargs,
)
# take mean if 'm2o' comparison forced before
if isHindcast and comparison != __m2o:
bootstrapped_uninit_skill = bootstrapped_uninit_skill.mean("member")
bootstrapped_hind = resample_func(hind, iterations, resample_dim)
if dask.is_dask_collection(bootstrapped_hind):
bootstrapped_hind = bootstrapped_hind.chunk({"member": -1})
bootstrapped_init_skill = compute(
bootstrapped_hind,
verif,
metric=metric,
comparison=comparison,
add_attrs=False,
dim=dim,
**metric_kwargs,
)
if "persistence" in reference:
pers_skill = compute_persistence(
hind,
verif,
metric=metric,
dim=dim,
**metric_kwargs_reference,
)
# bootstrap pers
if resample_dim == "init":
bootstrapped_pers_skill = compute_persistence(
bootstrapped_hind,
verif,
metric=metric,
**metric_kwargs_reference,
)
else: # member no need to calculate all again
bootstrapped_pers_skill, _ = xr.broadcast(
pers_skill, bootstrapped_init_skill
)
# calc mean skill without any resampling
init_skill = compute(
hind,
verif,
metric=metric,
comparison=comparison,
dim=dim,
**metric_kwargs,
)
if "uninitialized" in reference:
# uninit skill as mean resampled uninit skill
unin_skill = bootstrapped_uninit_skill.mean("iteration") # noqa: F841
if "persistence" in reference:
pers_skill = compute_persistence(
hind, verif, metric=metric, dim=dim, **metric_kwargs_reference
)
if "climatology" in reference:
clim_skill = compute_climatology(
hind, verif, metric=metric, dim=dim, comparison=comparison, **metric_kwargs
)
bootstrapped_clim_skill, _ = xr.broadcast(clim_skill, bootstrapped_init_skill)
# get confidence intervals CI
init_ci = _distribution_to_ci(bootstrapped_init_skill, ci_low, ci_high)
if "uninitialized" in reference:
unin_ci = _distribution_to_ci( # noqa: F841
bootstrapped_uninit_skill, ci_low, ci_high
)
if "climatology" in reference:
clim_ci = _distribution_to_ci( # noqa: F841
bootstrapped_clim_skill, ci_low, ci_high
)
if "persistence" in reference:
pers_ci = _distribution_to_ci( # noqa: F841
bootstrapped_pers_skill, ci_low_pers, ci_high_pers
)
# pvalue whether uninit or pers better than init forecast
if "uninitialized" in reference:
p_unin_over_init = _pvalue_from_distributions( # noqa: F841
bootstrapped_uninit_skill, bootstrapped_init_skill, metric=metric
)
if "climatology" in reference:
p_clim_over_init = _pvalue_from_distributions( # noqa: F841
bootstrapped_clim_skill, bootstrapped_clim_skill, metric=metric
)
if "persistence" in reference:
p_pers_over_init = _pvalue_from_distributions( # noqa: F841
bootstrapped_pers_skill, bootstrapped_init_skill, metric=metric
)
# gather return
# p defined as probability that reference better than
# initialized, therefore not defined for initialized skill
# itself
results = xr.concat(
[
init_skill,
init_skill.where(init_skill == -999),
init_ci.isel(quantile=0, drop=True),
init_ci.isel(quantile=1, drop=True),
],
dim="results",
coords="minimal",
).assign_coords(
results=("results", ["verify skill", "p", "low_ci", "high_ci"]),
skill="initialized",
)
if reference != []:
for r in reference:
ref_skill = eval(f"{r[:4]}_skill")
ref_p = eval(f"p_{r[:4]}_over_init")
ref_ci_low = eval(f"{r[:4]}_ci").isel(quantile=0, drop=True)
ref_ci_high = eval(f"{r[:4]}_ci").isel(quantile=1, drop=True)
ref_results = xr.concat(
[ref_skill, ref_p, ref_ci_low, ref_ci_high],
dim="results",
**CONCAT_KWARGS,
).assign_coords(
skill=r, results=("results", ["verify skill", "p", "low_ci", "high_ci"])
)
if "member" in ref_results.dims:
if not ref_results["member"].identical(results["member"]):
ref_results["member"] = results[
"member"
] # fixes m2c different member names in reference forecasts
results = xr.concat([results, ref_results], dim="skill", **CONCAT_KWARGS)
results = results.assign_coords(skill=["initialized"] + reference).squeeze()
else:
results = results.drop_sel(results="p")
results = results.squeeze()
# Attach climpred compute information to skill
# results.results
metadata_dict = {
"confidence_interval_levels": f"{ci_high}-{ci_low}",
"bootstrap_iterations": iterations,
}
if reference is not None:
metadata_dict[
"p"
] = "probability that reference performs better than initialized"
metadata_dict.update(metric_kwargs)
results = assign_attrs(
results,
hind,
alignment=alignment,
metric=metric,
comparison=comparison,
dim=dim,
metadata_dict=metadata_dict,
)
# Ensure that the lead units get carried along for the calculation. The attribute
# tends to get dropped along the way due to ``xarray`` functionality.
results["lead"] = hind["lead"]
if "units" in hind["lead"].attrs and "units" not in results["lead"].attrs:
results["lead"].attrs["units"] = hind["lead"].attrs["units"]
return results
start = (37.0, -105.0)
end = (35.5, -65.0)
##############################
# Get the cross section, and convert lat/lon to supplementary coordinates:
cross = cross_section(data, start, end)
cross.set_coords(('lat', 'lon'), True)
print(cross)
##############################
# For this example, we will be plotting potential temperature, relative humidity, and
# tangential/normal winds. And so, we need to calculate those, and add them to the dataset:
temperature, pressure, specific_humidity = xr.broadcast(cross['Temperature'],
cross['isobaric'],
cross['Specific_humidity'])
theta = mpcalc.potential_temperature(pressure, temperature)
rh = mpcalc.relative_humidity_from_specific_humidity(specific_humidity, temperature, pressure)
# These calculations return unit arrays, so put those back into DataArrays in our Dataset
cross['Potential_temperature'] = xr.DataArray(theta,
coords=temperature.coords,
dims=temperature.dims,
attrs={'units': theta.units})
cross['Relative_humidity'] = xr.DataArray(rh,
coords=specific_humidity.coords,
dims=specific_humidity.dims,
attrs={'units': rh.units})
def smape(a, b, dim=None, weights=None, skipna=False, keep_attrs=False):
"""Symmetric Mean Absolute Percentage Error.
.. math::
\\mathrm{SMAPE} = \\frac{1}{n} \\sum_{i=1}^{n}
\\frac{ \\vert a_{i} - b_{i} \\vert }
{ \\vert a_{i} \\vert + \\vert b_{i} \\vert }
.. note::
Percent error is reported as decimal percent. I.e., a value of 1 is
100%.
Parameters
----------
a : xarray.Dataset or xarray.DataArray
Labeled array(s) over which to apply the function.
(Truth which will be divided by)
b : xarray.Dataset or xarray.DataArray
Labeled array(s) over which to apply the function.
dim : str, list
The dimension(s) to apply the smape along. Note that this dimension will
be reduced as a result. Defaults to None reducing all dimensions.
weights : xarray.Dataset or xarray.DataArray or None
Weights matching dimensions of ``dim`` to apply during the function.
skipna : bool
If True, skip NaNs when computing function.
keep_attrs : bool
If True, the attributes (attrs) will be copied
from the first input to the new one.
If False (default), the new object will
be returned without attributes.
Returns
-------
xarray.Dataset or xarray.DataArray
Symmetric Mean Absolute Percentage Error.
References
----------
https://en.wikipedia.org/wiki/Symmetric_mean_absolute_percentage_error
Examples
--------
>>> import numpy as np
>>> import xarray as xr
>>> from xskillscore import smape
>>> a = xr.DataArray(np.random.rand(5, 3, 3),
dims=['time', 'x', 'y'])
>>> b = xr.DataArray(np.random.rand(5, 3, 3),
dims=['time', 'x', 'y'])
>>> smape(a, b, dim='time')
"""
dim, axis = _preprocess_dims(dim, a)
a, b = xr.broadcast(a, b, exclude=dim)
weights = _preprocess_weights(a, dim, dim, weights)
input_core_dims = _determine_input_core_dims(dim, weights)
return xr.apply_ufunc(
_smape,
a,
b,
weights,
input_core_dims=input_core_dims,
kwargs={
"axis": axis,
"skipna": skipna
},
dask="parallelized",
output_dtypes=[float],
keep_attrs=keep_attrs,
)
def create_raster_polygons(ds,
mask=None,subset_bbox=None,
weights=None,weights_target='ds'):
""" Create polygons for each pixel in a raster
Keyword arguments:
ds -- an xarray dataset with the variables
'lat_bnds' and 'lon_bnds', which are both
lat/lon x 2 arrays giving the min and
max values of lat and lon for each pixel
given by lat/lon
subset_bbox -- by default None; if a geopandas
geodataframe is entered, the bounding
box around the geometries in the gdf
are used to mask the grid, to reduce
the number of pixel polygons created
mask -- ## THIS IS WHERE MASKS CAN BE ADDED -
# I.E. AN OCEAN MASK. OR MAYBE EVEN ALLOW
# SHAPEFILES TO BE ADDED AND CALCULATED
# THE MASKED PIXELS ARE JUST IGNORED, AND NOT
# ADDED. will make identifying them harder
# in the first bit of aggregate, but could
# make processing faster if you have a ton
# of ocean pixels or something...
Returns:
a geopandas geodataframe containing a 'geometry'
giving the pixel boundaries for each 'lat' / 'lon'
pair
Note:
'lat_bnds' and 'lon_bnds' can be created through the
'get_bnds' function if they are not already included
in the input raster file.
Note:
Currently this code only supports regular
rectangular grids (so where every pixel side is
a straight line in lat/lon space). Future versions
may include support for irregular grids.
"""
# Standardize inputs
ds = fix_ds(ds)
ds = get_bnds(ds)
#breakpoint()
# Subset by shapefile bounding box, if desired
if subset_bbox is not None:
if type(subset_bbox) is gpd.geodataframe.GeoDataFrame:
# Using the biggest difference in lat/lon to make sure that the pixels are subset
# in a way that the bounding box is fully filled out
bbox_thresh = np.max([ds.lat.diff('lat').max(),ds.lon.diff('lon').max()])+0.1
ds = ds.sel(lon=slice(subset_bbox.total_bounds[0]-bbox_thresh,subset_bbox.total_bounds[2]+bbox_thresh),
lat=slice(subset_bbox.total_bounds[1]-bbox_thresh,subset_bbox.total_bounds[3]+bbox_thresh))
else:
warnings.warn('[subset_bbox] is not a geodataframe; no mask by polygon bounding box used.')
# Process weights
ds,winf = process_weights(ds,weights,target=weights_target)
# Mask
if mask is not None:
warnings.warn('Masking by grid not yet supported. Stay tuned...')
# Create dataset which has a lat/lon bound value for each individual pixel,
# broadcasted out over each lat/lon pair
(ds_bnds,) = (xr.broadcast(ds.isel({d:0 for d in [k for k in ds.dims.keys() if k not in ['lat','lon','bnds']]}).
drop_vars([v for v in ds.keys() if v not in ['lat_bnds','lon_bnds']])))
# Stack so it's just pixels and bounds
ds_bnds = ds_bnds.stack(loc=('lat','lon'))
# In order:
# (lon0,lat0),(lon0,lat1),(lon1,lat1),(lon1,lat1), but as a single array; to be
# put in the right format for Polygon in the next step
pix_poly_coords = np.transpose(np.vstack([ds_bnds.lon_bnds.isel(bnds=0).values,ds_bnds.lat_bnds.isel(bnds=0).values,
ds_bnds.lon_bnds.isel(bnds=0).values,ds_bnds.lat_bnds.isel(bnds=1).values,
ds_bnds.lon_bnds.isel(bnds=1).values,ds_bnds.lat_bnds.isel(bnds=1).values,
ds_bnds.lon_bnds.isel(bnds=1).values,ds_bnds.lat_bnds.isel(bnds=0).values]))
# Reshape so each location has a 4 x 2 (vertex vs coordinate) array,
# and convert each of those vertices to tuples. This means every element
# of pix_poly_coords is the input to shapely.geometry.Polygon of one pixel
pix_poly_coords = tuple(map(tuple,np.reshape(pix_poly_coords,(np.shape(pix_poly_coords)[0],4,2))))
# Create empty geodataframe
gdf_pixels = gpd.GeoDataFrame()
gdf_pixels['lat'] = [None]*ds_bnds.dims['loc']
gdf_pixels['lon'] = [None]*ds_bnds.dims['loc']
gdf_pixels['geometry'] = [None]*ds_bnds.dims['loc']
if weights is not None:
# Stack weights so they are linearly indexed like the ds (and fill
# NAs with 0s)
weights = ds.weights.stack(loc=('lat','lon')).fillna(0)
# Preallocate weights column
gdf_pixels['weights'] = [None]*ds_bnds.dims['loc']
# Now populate with a polygon for every pixel, and the lat/lon coordinates
# of that pixel (Try if preallocating it with the right dimensions above
# makes it faster, because it's pretty slow rn (NB: it doesn't really))
for loc_idx in np.arange(0,ds_bnds.dims['loc']):
gdf_pixels.loc[loc_idx,'lat'] = ds_bnds.lat.isel(loc=loc_idx).values
gdf_pixels.loc[loc_idx,'lon'] = ds_bnds.lon.isel(loc=loc_idx).values
gdf_pixels.loc[loc_idx,'geometry'] = Polygon(pix_poly_coords[loc_idx])
if weights is not None:
gdf_pixels.loc[loc_idx,'weights'] = weights.isel(loc=loc_idx).values
# Add a "pixel idx" to make indexing better later
gdf_pixels['pix_idx'] = gdf_pixels.index.values
# Add crs (normal lat/lon onto WGS84)
gdf_pixels = gdf_pixels.set_crs("EPSG:4326")
# Save the source grid for further reference
source_grid = {'lat':ds_bnds.lat,'lon':ds_bnds.lon}
pix_agg = {'gdf_pixels':gdf_pixels,'source_grid':source_grid}
# Return the created geodataframe
return pix_agg
def pearson_r_p_value(a,
b,
dim=None,
weights=None,
skipna=False,
keep_attrs=False):
"""2-tailed p-value associated with pearson's correlation coefficient.
Parameters
----------
a : xarray.Dataset or xarray.DataArray
Labeled array(s) over which to apply the function.
b : xarray.Dataset or xarray.DataArray
Labeled array(s) over which to apply the function.
dim : str, list
The dimension(s) to apply the correlation along. Note that this dimension will
be reduced as a result. Defaults to None reducing all dimensions.
weights : xarray.Dataset or xarray.DataArray or None
Weights matching dimensions of ``dim`` to apply during the function.
skipna : bool
If True, skip NaNs when computing function.
keep_attrs : bool
If True, the attributes (attrs) will be copied
from the first input to the new one.
If False (default), the new object will
be returned without attributes.
Returns
-------
xarray.Dataset or xarray.DataArray
2-tailed p-value of Pearson's correlation coefficient.
See Also
--------
scipy.stats.pearsonr
Examples
--------
>>> import numpy as np
>>> import xarray as xr
>>> from xskillscore import pearson_r_p_value
>>> a = xr.DataArray(np.random.rand(5, 3, 3),
dims=['time', 'x', 'y'])
>>> b = xr.DataArray(np.random.rand(5, 3, 3),
dims=['time', 'x', 'y'])
>>> pearson_r_p_value(a, b, dim='time')
"""
_fail_if_dim_empty(dim)
dim, _ = _preprocess_dims(dim, a)
a, b = xr.broadcast(a, b, exclude=dim)
a, b, new_dim, weights = _stack_input_if_needed(a, b, dim, weights)
weights = _preprocess_weights(a, dim, new_dim, weights)
input_core_dims = _determine_input_core_dims(new_dim, weights)
return xr.apply_ufunc(
_pearson_r_p_value,
a,
b,
weights,
input_core_dims=input_core_dims,
kwargs={
"axis": -1,
"skipna": skipna
},
dask="parallelized",
output_dtypes=[float],
keep_attrs=keep_attrs,
)
def _plot_transect(self, remappedModelClimatology, remappedRefClimatology):
# {{{
""" plotting the transect """
season = self.season
config = self.config
configSectionName = self.configSectionName
mainRunName = config.get('runs', 'mainRunName')
# broadcast x and z to have the same dimensions
x, z = xr.broadcast(remappedModelClimatology.x,
remappedModelClimatology.z)
# set lat and lon in case we want to plot versus these quantities
lat = remappedModelClimatology.lat
lon = remappedModelClimatology.lon
# convert x, z, lat, and lon to numpy arrays; make a copy because
# they are sometimes read-only (not sure why)
x = x.values.copy().transpose()
z = z.values.copy().transpose()
lat = lat.values.copy().transpose()
lon = lon.values.copy().transpose()
self.lat = lat
self.lon = lon
# z is masked out with NaNs in some locations (where there is land) but
# this makes pcolormesh unhappy so we'll zero out those locations
z[numpy.isnan(z)] = 0.
modelOutput = nans_to_numpy_mask(
remappedModelClimatology[self.mpasFieldName].values)
modelOutput = modelOutput.transpose()
if remappedRefClimatology is None:
refOutput = None
bias = None
else:
refOutput = remappedRefClimatology[self.refFieldName]
dims = refOutput.dims
refOutput = nans_to_numpy_mask(refOutput.values)
if dims[1] != 'nPoints':
assert (dims[0] == 'nPoints')
refOutput = refOutput.transpose()
bias = modelOutput - refOutput
filePrefix = self.filePrefix
outFileName = '{}/{}.png'.format(self.plotsDirectory, filePrefix)
title = '{}\n({}, years {:04d}-{:04d})'.format(self.fieldNameInTitle,
season, self.startYear,
self.endYear)
xLabel = 'Distance [km]'
yLabel = 'Depth [m]'
# define the axis labels and the data to use for the upper
# x axis or axes, if such additional axes have been requested
upperXAxes = config.get('transects', 'upperXAxes')
numUpperTicks = config.getint('transects', 'numUpperTicks')
upperXAxisTickLabelPrecision = config.getint(
'transects', 'upperXAxisTickLabelPrecision')
self._set_third_x_axis_to_none()
if upperXAxes == 'neither':
self._set_second_x_axis_to_none()
elif upperXAxes == 'lat':
self._set_second_x_axis_to_latitude()
elif upperXAxes == 'lon':
self._set_second_x_axis_to_longitude()
elif upperXAxes == 'both':
self._set_second_x_axis_to_longitude()
self._set_third_x_axis_to_latitude()
elif upperXAxes == 'greatestExtent':
if self._greatest_extent(lat, lon):
self._set_second_x_axis_to_latitude()
else:
self._set_second_x_axis_to_longitude()
elif upperXAxes == 'strictlyMonotonic':
if self._strictly_monotonic(lat, lon):
self._set_second_x_axis_to_latitude()
else:
self._set_second_x_axis_to_longitude()
elif upperXAxes == 'mostMonotonic':
if self._most_monotonic(lat, lon):
self._set_second_x_axis_to_latitude()
else:
self._set_second_x_axis_to_longitude()
elif upperXAxes == 'mostStepsInSameDirection':
if self._most_steps_in_same_direction(lat, lon):
self._set_second_x_axis_to_latitude()
else:
self._set_second_x_axis_to_longitude()
elif upperXAxes == 'fewestDirectionChanges':
if self._fewest_direction_changes(lat, lon):
self._set_second_x_axis_to_latitude()
else:
self._set_second_x_axis_to_longitude()
else:
raise ValueError('invalid option for upperXAxes')
# get the parameters determining what type of plot to use,
# what line styles and line colors to use, and whether and how
# to label contours
compareAsContours = config.getboolean('transects',
'compareAsContoursOnSinglePlot')
contourLineStyle = config.get('transects', 'contourLineStyle')
contourLineColor = config.get('transects', 'contourLineColor')
comparisonContourLineStyle = config.get('transects',
'comparisonContourLineStyle')
comparisonContourLineColor = config.get('transects',
'comparisonContourLineColor')
if compareAsContours:
labelContours = config.getboolean(
'transects', 'labelContoursOnContourComparisonPlots')
else:
labelContours = config.getboolean('transects',
'labelContoursOnHeatmaps')
contourLabelPrecision = config.getint('transects',
'contourLabelPrecision')
# construct a three-panel comparison plot for the transect, or a
# single-panel contour comparison plot if compareAsContours is True
plot_vertical_section_comparison(
config,
x,
z,
modelOutput,
refOutput,
bias,
outFileName,
configSectionName,
cbarLabel=self.unitsLabel,
xlabel=xLabel,
ylabel=yLabel,
title=title,
modelTitle='{}'.format(mainRunName),
refTitle=self.refTitleLabel,
diffTitle=self.diffTitleLabel,
secondXAxisData=self.secondXAxisData,
secondXAxisLabel=self.secondXAxisLabel,
thirdXAxisData=self.thirdXAxisData,
thirdXAxisLabel=self.thirdXAxisLabel,
numUpperTicks=numUpperTicks,
upperXAxisTickLabelPrecision=upperXAxisTickLabelPrecision,
invertYAxis=False,
backgroundColor='#918167',
compareAsContours=compareAsContours,
lineStyle=contourLineStyle,
lineColor=contourLineColor,
comparisonContourLineStyle=comparisonContourLineStyle,
comparisonContourLineColor=comparisonContourLineColor,
labelContours=labelContours,
contourLabelPrecision=contourLabelPrecision)
caption = '{} {}'.format(season, self.imageCaption)
write_image_xml(config,
filePrefix,
componentName='Ocean',
componentSubdirectory='ocean',
galleryGroup=self.galleryGroup,
groupSubtitle=self.groupSubtitle,
groupLink=self.groupLink,
gallery=self.galleryName,
thumbnailDescription=self.thumbnailDescription,
imageDescription=caption,
imageCaption=caption)
def gen_ds():
for val, d in ds.groupby(dim):
del d[dim] # delete grouped labels
d[dim] = [val]
d, = xr.broadcast(d)
yield d
def apply_param_noise(ds,
params,
noise_types,
shape=(0, ),
noise_sds=[0],
seed=0):
"""Apply noise to each timestep for each Monte Carlo draw of the outbreak
simulations.
Parameters
----------
ds : :class:`xarray.Dataset`
A Dataset that has variables called ``[varname]_deterministic`` for each of the
parameters in `params`.
params : list of str
The name of the params in this dataset (e.g. ``beta, gamma, sigma`` for SEIR and
``beta, gamma`` for SIR).
noise_types : list of str
Same length as `params`. Each element is one of ``["normal", "exponential",
False]``. This defines the type of noise applied to each. False means no noise.
shape : tuple of int, optional
(n_samples, n_timesteps). Only needed if any `noise_types` are ``normal``
noise_sds : list of float
Standard deviations to use for any parameters with ``noise_type=="normal"``.
Must be same length as `params` but unused for any params with other
`noise_type`.
seed : int
Random seed for generating noise
Returns
-------
out : :class:`xarray.Dataset`
Same as `ds` but with ``[varname]_stoch`` stochastic variables added.
"""
np.random.seed(seed)
for px, param in enumerate(params):
noise_type = noise_types[px]
noise_sd = noise_sds[px]
param_stoch = param + "_stoch"
param_det = param + "_deterministic"
if noise_type is None:
continue
elif noise_type == "normal":
ds[param_stoch] = (
("sample", "t"),
np.random.normal(0, noise_sd, shape),
)
ds[param_stoch] = ds[param_det] + ds[param_stoch]
elif noise_type == "exponential":
(ds[param_det], _, _) = xr.broadcast(ds[param_det], ds.sample,
ds.t)
ds[param_stoch] = (
ds[param_det].dims,
np.random.exponential(ds[param_det]),
)
# commented out b/c inverse-exponential has undefined expected value
# and empirically changes the mean parameter by order(s) of magnitude
# elif noise_type == "inv_exponential":
# (out[param_det],_,_) = xr.broadcast(
# out[param_det],
# out.sample,
# out.t)
# out[param_stoch] = (
# out[param_det].dims,
# 1/np.random.exponential(1/out[param_det])
# )
elif not noise_type:
ds[param_stoch] = ds[param_det].copy()
else:
raise ValueError(noise_type)
neg = ds[param_stoch] < 0
n_bad = neg.sum().item()
if n_bad > 0:
n_tot = np.prod(ds[param_stoch].shape)
dims = ["gamma"]
if "sigma" in ds[param_stoch].dims:
dims.append("sigma")
to_sum = [d for d in ds[param_stoch].dims if d not in dims]
cross_tab = (neg.sum(to_sum) / neg.count(to_sum)).to_dataframe()
warnings.warn(
f"Parameter {param} has {n_bad}/{n_tot} values <0 ({n_bad/n_tot:.2%}). "
"These are non-physical params. If they are dropped in the simulation, "
f"this will change the mean. Fraction of negative values: {cross_tab}"
)
return ds
#########################################################################
# Calculations
# ------------
#
# Most of the calculations in `metpy.calc` will accept DataArrays by converting them
# into their corresponding unit arrays. While this may often work without any issues, we must
# keep in mind that because the calculations are working with unit arrays and not DataArrays:
#
# - The calculations will return unit arrays rather than DataArrays
# - Broadcasting must be taken care of outside of the calculation, as it would only recognize
# dimensions by order, not name
#
# As an example, we calculate geostropic wind at 500 hPa below:
lat, lon = xr.broadcast(y, x)
f = mpcalc.coriolis_parameter(lat)
dx, dy = mpcalc.lat_lon_grid_deltas(lon, lat, initstring=data_crs.proj4_init)
heights = data['height'].metpy.loc[{'time': time[0], 'vertical': 500. * units.hPa}]
u_geo, v_geo = mpcalc.geostrophic_wind(heights, f, dx, dy)
print(u_geo)
print(v_geo)
#########################################################################
# Also, a limited number of calculations directly support xarray DataArrays or Datasets (they
# can accept *and* return xarray objects). Right now, this includes
#
# - Derivative functions
# - ``first_derivative``
# - ``second_derivative``
# - ``gradient``
def gen_xy():
for i, z in enumerate(self._z_vals):
das = {}
data = {}
# multiple data variables rather than z coordinate
if self._multi_var:
das['x'] = self._ds[self.x_coo]
das['y'] = self._ds[z]
if (self.y_err is not None) or \
(self.x_err is not None) or \
(self.c_coo is not None):
raise ValueError('Multi-var errors/c not implemented.')
# z-coordinate to iterate over
elif z is not None:
try:
# try positional indexing first, as much faster
sub_ds = self._ds[{self.z_coo: i}]
except ValueError:
# but won't work e.g. on non-dimensions
sub_ds = self._ds.loc[{self.z_coo: z}]
das['x'] = sub_ds[self.x_coo]
das['y'] = sub_ds[self.y_coo]
if self.c_coo is not None:
if mode == 'lineplot':
self._c_cols.append(np.asscalar(
sub_ds[self.c_coo].values.flatten()))
elif mode == 'scatter':
das['c'] = sub_ds[self.c_coo]
if self.y_err is not None:
das['ye'] = sub_ds[self.y_err]
if self.x_err is not None:
das['xe'] = sub_ds[self.x_err]
# nothing to iterate over
else:
das['x'] = self._ds[self.x_coo]
das['y'] = self._ds[self.y_coo]
if self.c_coo is not None:
if mode == 'lineplot':
self._c_cols.append(np.asscalar(
self._ds[self.c_coo].values.flatten()))
elif mode == 'scatter':
das['c'] = self._ds[self.c_coo]
if self.y_err is not None:
das['ye'] = self._ds[self.y_err]
if self.x_err is not None:
das['xe'] = self._ds[self.x_err]
for k, da in zip(das, xr.broadcast(*das.values())):
data[k] = da.values.flatten()
# Trim out missing data
not_null = np.isfinite(data['x'])
not_null &= np.isfinite(data['y'])
# TODO: if scatter, broadcast *then* ravel x, y, c?
data['x'] = data['x'][not_null]
data['y'] = data['y'][not_null]
# implement jitter
if self.xjitter:
if self.xlog:
data['x'] = data['x'] * np.random.normal(
loc=1, scale=self.xjitter, size=data['x'].shape)
else:
data['x'] = data['x'] + np.random.normal(
loc=0, scale=self.xjitter, size=data['x'].shape)
if self.yjitter:
if self.ylog:
data['y'] = data['y'] * np.random.normal(
loc=1, scale=self.yjitter, size=data['y'].shape)
else:
data['y'] = data['y'] + np.random.normal(
loc=0, scale=self.yjitter, size=data['y'].shape)
if 'c' in data:
data['c'] = data['c'][not_null]
if 'ye' in data:
data['ye'] = data['ye'][not_null]
if 'xe' in data:
data['xe'] = data['xe'][not_null]
yield data
# ------------
#
# Nearly all of the calculations in `metpy.calc` will accept DataArrays by converting them
# into their corresponding unit arrays. While this may often work without any issues, we must
# keep in mind that because the calculations are working with unit arrays and not DataArrays:
#
# - The calculations will return unit arrays rather than DataArrays
# - Broadcasting must be taken care of outside of the calculation, as it would only recognize
# dimensions by order, not name
#
# Also, some of the units used in CF conventions (such as 'degrees_north') are not recognized
# by pint, so we must implement a workaround.
#
# As an example, we calculate geostropic wind at 500 hPa below:
lat, lon = xr.broadcast(y, x)
f = mpcalc.coriolis_parameter(lat.values * units.degrees)
dx, dy = mpcalc.lat_lon_grid_deltas(lon.values, lat.values)
heights = data['height'].loc[time[0]].loc[{vertical.name: 500.}]
u_geo, v_geo = mpcalc.geostrophic_wind(heights, f, dx, dy, dim_order='yx')
print(u_geo)
print(v_geo)
#########################################################################
# Plotting
# --------
#
# Like most meteorological data, we want to be able to plot these data. DataArrays can be used
# like normal numpy arrays in plotting code, or we can use some of xarray's plotting
# functionality.
#
def weights_lonlat(a):
weights = np.cos(np.deg2rad(a.lat))
_, weights = xr.broadcast(a, weights)
return weights.isel(time=0, drop=True)
def add_time_dimension(data, model_run):
"""
Once all constraints and costs have been loaded into the model dataset, any
timeseries data is loaded from file and substituted into the model dataset
Parameters:
-----------
data : xarray Dataset
A data structure which has already gone through `constraints_to_dataset`,
`costs_to_dataset`, and `add_attributes`
model_run : AttrDict
Calliope model_run dictionary
Returns:
--------
data : xarray Dataset
A data structure with an additional time dimension to the input dataset,
with all relevant `file=` entries replaced with data from file.
"""
data['timesteps'] = pd.to_datetime(data.timesteps)
# Search through every constraint/cost for use of '='
for variable in data.data_vars:
# 1) If '=' in variable, it will give the variable a string data type
if data[variable].dtype.kind != 'U':
continue
# 2) convert to a Pandas Series to do 'string contains' search
data_series = data[variable].to_series()
# 3) get a Series of all the uses of 'file=' for this variable
filenames = data_series[data_series.str.contains('file=')]
# 4) If no use of 'file=' then we can be on our way
if filenames.empty:
continue
# 5) remove all before '=' and split filename and location column
filenames = filenames.str.split('=').str[1].str.rsplit(':', 1)
if isinstance(filenames.index, pd.MultiIndex):
filenames.index = filenames.index.remove_unused_levels()
# 6) Get all timeseries data from dataframes stored in model_run
timeseries_data = []
key_errors = []
for loc_tech, (filename, column) in filenames.iteritems():
try:
timeseries_data.append(
model_run.timeseries_data[filename].loc[:, column].values)
except KeyError:
key_errors.append(
'column `{}` not found in file `{}`, but was requested by '
'loc::tech `{}`.'.format(column, filename, loc_tech))
if key_errors:
exceptions.print_warnings_and_raise_errors(errors=key_errors)
timeseries_data_series = pd.DataFrame(index=filenames.index,
columns=data.timesteps.values,
data=timeseries_data).stack()
timeseries_data_series.index.rename('timesteps', -1, inplace=True)
# 7) Add time dimension to the relevent DataArray and update the '='
# dimensions with the time varying data (static data is just duplicated
# at each timestep)
timeseries_data_array = xr.broadcast(data[variable],
data.timesteps)[0].copy()
timeseries_data_array.loc[xr.DataArray.from_series(
timeseries_data_series).coords] = xr.DataArray.from_series(
timeseries_data_series).values
# 8) assign correct dtype (might be string/object accidentally)
# string 'nan' to NaN:
array_to_check = timeseries_data_array.where(
timeseries_data_array != 'nan', drop=True)
timeseries_data_array = timeseries_data_array.where(
timeseries_data_array != 'nan')
if ((array_to_check == 'True') | (array_to_check == '1') |
(array_to_check == 'False') |
(array_to_check == '0')).all().item():
# Turn to bool
timeseries_data_array = ((timeseries_data_array == 'True') |
(timeseries_data_array == '1')).copy()
else:
try:
timeseries_data_array = timeseries_data_array.astype(
np.float, copy=False)
except ValueError:
None
data[variable] = timeseries_data_array
# Add timestep_resolution by looking at the time difference between timestep n
# and timestep n + 1 for all timesteps
time_delta = (data.timesteps.shift(timesteps=-1) -
data.timesteps).to_series()
# Last timestep has no n + 1, so will be NaT (not a time),
# we duplicate the penultimate time_delta instead
time_delta[-1] = time_delta[-2]
time_delta.name = 'timestep_resolution'
# Time resolution is saved in hours (i.e. seconds / 3600)
data['timestep_resolution'] = (xr.DataArray.from_series(
time_delta.dt.total_seconds() / 3600))
data['timestep_weights'] = xr.DataArray(np.ones(len(data.timesteps)),
dims=['timesteps'])
return data
def first_run(
da: xr.DataArray,
window: int,
dim: str = "time",
coord: Optional[Union[str, bool]] = False,
ufunc_1dim: Union[str, bool] = "auto",
) -> xr.DataArray:
"""Return the index of the first item of the first run of at least a given length.
Parameters
----------
da : xr.DataArray
Input N-dimensional DataArray (boolean).
window : int
Minimum duration of consecutive run to accumulate values.
dim : str
Dimension along which to calculate consecutive run (default: 'time').
coord : Optional[str]
If not False, the function returns values along `dim` instead of indexes.
If `dim` has a datetime dtype, `coord` can also be a str of the name of the
DateTimeAccessor object to use (ex: 'dayofyear').
ufunc_1dim : Union[str, bool]
Use the 1d 'ufunc' version of this function : default (auto) will attempt to select optimal
usage based on number of data points. Using 1D_ufunc=True is typically more efficient
for dataarray with a small number of gridpoints.
Returns
-------
xr.DataArray
Index (or coordinate if `coord` is not False) of first item in first valid run.
Returns np.nan if there are no valid runs.
"""
if ufunc_1dim == "auto":
if isinstance(da.data,
dsk.Array) and len(da.chunks[da.dims.index(dim)]) > 1:
ufunc_1dim = False
else:
npts = get_npts(da)
ufunc_1dim = npts <= npts_opt
da = da.fillna(
0) # We expect a boolean array, but there could be NaNs nonetheless
if ufunc_1dim:
out = first_run_ufunc(x=da, window=window, dim=dim)
else:
da = da.astype("int")
i = xr.DataArray(np.arange(da[dim].size), dims=dim)
ind = xr.broadcast(i, da)[0].transpose(*da.dims)
if isinstance(da.data, dsk.Array):
ind = ind.chunk(da.chunks)
wind_sum = da.rolling(time=window).sum(skipna=False)
out = ind.where(wind_sum >= window).min(dim=dim) - (window - 1)
# remove window - 1 as rolling result index is last element of the moving window
if coord:
crd = da[dim]
if isinstance(coord, str):
crd = getattr(crd.dt, coord)
out = lazy_indexing(crd, out)
if dim in out.coords:
out = out.drop_vars(dim)
return out
