def filter(self):
from ptsa.filt import buttfilt
# find index of the axis called 'time'
if self.time_axis<0:
time_index_array = np.where(np.array(self.time_series.dims) == 'time')
if len(time_index_array)>0:
self.time_axis =time_index_array[0] # picking first index that corresponds to the dimension
else:
raise RuntimeError("Could not locate 'time' axis in your time series."
" Make sure to either label appropriate axis of your time series 'time' or specify"
"time axis explicitely as a non-negative integer '")
filtered_array = buttfilt(self.time_series,
self.freq_range, self.samplerate, self.filt_type,
self.order,axis=self.time_axis)
self.filtered_time_series = xray.DataArray(
filtered_array,
coords = [xray.DataArray(coord.copy()) for coord_name, coord in self.time_series.coords.items() ]
)
# l = [xray.DataArray(coord.copy()) for coord_name, coord in self.time_series.coords.items() ]
return self.filtered_time_series
# attrs = self._attrs.copy()
# for k in self._required_attrs.keys():
# attrs.pop(k,None)
# return TimeSeries(filtered_array,self.tdim, self.samplerate,
# dims=self.dims.copy(), **attrs)
def write(self, filename, varname=None):
"""Write a :class:`Field` to a netcdf file
:param filename: Basename of the file
:param varname: Name of the field, to be appended to the filename"""
filepath = str(path.local('%s%s.nc' % (filename, self.name)))
if varname is None:
varname = self.name
# Derive name of 'depth' variable for NEMO convention
vname_depth = 'depth%s' % self.name.lower()
# Create DataArray objects for file I/O
t, d, x, y = (self.time.size, self.depth.size, self.lon.size,
self.lat.size)
nav_lon = xray.DataArray(self.lon + np.zeros((y, x), dtype=np.float32),
coords=[('y', self.lat), ('x', self.lon)])
nav_lat = xray.DataArray(self.lat.reshape(y, 1) +
np.zeros(x, dtype=np.float32),
coords=[('y', self.lat), ('x', self.lon)])
vardata = xray.DataArray(self.data.reshape((t, d, y, x)),
coords=[('time_counter', self.time),
(vname_depth, self.depth),
('y', self.lat), ('x', self.lon)])
# Create xray Dataset and output to netCDF format
dset = xray.Dataset({varname: vardata},
coords={
'nav_lon': nav_lon,
'nav_lat': nav_lat
})
dset.to_netcdf(filepath)
def to_xray(self, ndarray):
"""Create xray object matching original one from spharm object."""
# Re-expand collapsed non-lat/lon dims.
arr_orig = self._u
ax_lat_orig = arr_orig.get_axis_num(LAT_STR)
ax_lon_orig = arr_orig.get_axis_num(LON_STR)
ax_other_dims = set(range(arr_orig.ndim)) - {ax_lat_orig, ax_lon_orig}
shape_other_dims = [
axlen for n, axlen in enumerate(arr_orig.shape)
if n in ax_other_dims
]
arr_new = ndarray.reshape([ndarray.shape[0], ndarray.shape[1]] +
shape_other_dims)
# Return to original axis order.
arr_new = np.rollaxis(arr_new, 2, 0)
if arr_orig.ndim == 4:
arr_new = np.rollaxis(arr_new, -1, 1)
# Return to original latitude orientation.
# If the original array got flipped, flip it back.
if self.flag_flip_lat(arr_orig, out_north_to_south=True):
arr_new = np.swapaxes(
arr_new.swapaxes(ax_lat_orig, 0)[::-1], ax_lat_orig, 0)
# Reapply the mask and return to an xray object.
return xray.DataArray(np.ma.array(arr_new, mask=self.mask),
dims=arr_orig.dims,
coords=arr_orig.coords)
def compute_mtf(self):
""" Compute the MTF of a FocalPlaneArray. In this model, the FPA is assumed to be a rectangular array
having pixels with rectangular aperture.
:return:
"""
# First set up a set of spatial frequencies up to a factor of 20 times the pixel nyquist
nyquist_x = 1.0/(2.0*self.pitchx.data) # cy/mm
self.nyquist_x = Scalar('nyqx', nyquist_x, '1/' + self.pitchx.units)
nyquist_y = 1.0/(2.0*self.pitchy.data) # cy/mm
self.nyquist_y = Scalar('nyqy', nyquist_y, '1/' + self.pitchy.units)
# Generate a relative set of spatial frequencies, with variable spacing up to 20 times relative nyquist
spf_rel = np.hstack((np.linspace(0., 1, 10), np.linspace(1., 2, 9), np.linspace(2. ,3, 7),
np.linspace(3., 4, 7), np.linspace(4., 5, 7), np.linspace(5. ,6, 5),
np.linspace(6., 7, 5), np.linspace(7., 8, 5), np.linspace(8. ,9 ,3),
np.linspace(9., 10, 3))) # Will use sinc function up to argument of 10
spf_rel = np.unique(spf_rel) # Will be duplication at the zeroes
spf_x = spf_rel * nyquist_x * 2.0
spf_y = spf_rel * nyquist_y * 2.0
spf = xd_identity(np.unique(np.hstack((spf_x, spf_y))), 'spf', attrs={'units': '1/mm'}) # Create spat freq axis
self.spf = spf
# Get back spf_rel, which could be different in x and y directions
spf_rel_x = spf.data / (nyquist_x * 2.0)
spf_rel_y = spf.data / (nyquist_y * 2.0)
fldo = xd_identity([0.0, 90.0], 'fldo')
self.mtf = xray.DataArray(np.sinc(np.vstack((spf_rel_x, spf_rel_y))).T,
[(spf), (fldo)],
name='mtf', attrs={'units': ''})
def _read_one_signal(connection, signal):
""" Read one signal through the connection """
if 'oned' in signal:
dimensions = {0: 'time'}
elif 'twod' in signal:
dimensions = {0: 'rho', 1: 'time'}
else:
raise NotImplementedError
data = connection.get(signal)
coords = {}
units = {}
for i in xrange(2):
dim = r'dim_of({}, {})'.format(signal, i)
unit = r'units_of({})'.format(dim)
try:
coords[dimensions[i]] = connection.get(dim)
units[dimensions[i]] = connection.get(unit)
except mds.MdsException:
break
# FIXME why do we need the transpose here?
return xray.DataArray(data.T, coords, attrs={'units': units})
def cyclic_dataarray(da, coord='lon'):
""" Add a cyclic coordinate point to a DataArray along a specified
named coordinate dimension.
>>> from xray import DataArray
>>> data = DataArray([[1, 2, 3], [4, 5, 6]],
... coords={'x': [1, 2], 'y': range(3)},
... dims=['x', 'y'])
>>> cd = cyclic_dataarray(data, 'y')
>>> print cd.data
array([[1, 2, 3, 1],
[4, 5, 6, 4]])
"""
assert isinstance(da, xray.DataArray)
lon_idx = da.dims.index(coord)
cyclic_data, cyclic_coord = add_cyclic_point(da.values,
coord=da.coords[coord],
axis=lon_idx)
# Copy and add the cyclic coordinate and data
new_coords = dict(da.coords)
new_coords[coord] = cyclic_coord
new_values = cyclic_data
new_da = xray.DataArray(new_values, dims=da.dims, coords=new_coords)
# Copy the attributes for the re-constructed data and coords
for att, val in da.attrs.items():
new_da.attrs[att] = val
for c in da.coords:
for att in da.coords[c].attrs:
new_da.coords[c].attrs[att] = da.coords[c].attrs[att]
return new_da
def season_mean(ds, calendar='standard'):
"""
Calculate the seasonal mean from a xray Dataset of monthly means. Weight
the means by the number of days in each month.
Parameters
----------
ds : xray.Dataset
Monthly frequency Pandas DatetimeIndex.
calendar : {'standard', 'gregorian', 'proleptic_gregorian', 'julian'}
netCDF calendar with leap years.
Returns
----------
seasonal_mean : xray.Dataset
Dataset representing the seasonal mean of `ds`.
"""
# Make a DataArray with the number of days in each month, size = len(time)
month_length = xray.DataArray(get_dpm(ds.time.to_index(),
calendar=calendar),
coords=[ds.time],
name='month_length')
# Calculate the weights by grouping by 'time.season'
weights = (month_length.groupby('time.season') /
month_length.groupby('time.season').sum())
# Test that the sum of the weights for each season is 1.0
np.testing.assert_allclose(
weights.groupby('time.season').sum().values, np.ones(4))
# Calculate the weighted average
return (ds * weights).groupby('time.season').sum(dim='time')
def diff_zp1_to_z(self, array, zname='Z', zp1name='Zp1'):
"""Take the vertical difference of an array located at zp1 points, resulting
in a new array at z points.
Parameters
----------
array : xray DataArray
The array to difference. Must have the coordinate zp1.
zname : str, optional
The variable name for the z point
zp1name : str, optional
The variable name for the zp1 point
Returns
-------
diff : xray DataArray
A new array with vertical coordinate z.
"""
a_up = array.isel(**{zp1name: slice(None, -1)})
a_dn = array.isel(**{zp1name: slice(1, None)})
a_diff = a_up.data - a_dn.data
# dimensions and coords of new array
coords, dims = self._get_coords_from_dims(array.dims,
replace={zp1name: zname})
return xray.DataArray(a_diff,
coords,
dims,
name=_append_to_name(array, 'diff_zp1_to_z'))
def dict_toxray(data, ds={}, **kwargs):
"""
Converts a dictionary with keys as variable names to an
xray.Dataset object
The dictionary keys should correspond with variable names in
ncmetadata.yaml
**kwargs are passed directly to xray.DataArray()
"""
for vv in list(data.keys()):
if vv in ncmeta:
attrs = ncmeta[vv]['attributes']
else:
print(
'Warning variable: %s not in ncmetadata.yaml. Dataset will have no attrs'
)
attrs = {}
da = xray.DataArray(data[vv], attrs=attrs, **kwargs)
ds.update({vv: da})
return xray.Dataset(ds)
def annual_mean(ds, calendar='standard'):
"""
Calculate the annual mean from a xray Dataset of monthly means. Weight
the means by the number of days in each month.
Parameters
----------
ds : xray.Dataset
Monthly frequency Pandas DatetimeIndex.
calendar : {'standard', 'gregorian', 'proleptic_gregorian', 'julian'}
netCDF calendar with leap years.
Returns
----------
seasonal_mean : xray.Dataset
Dataset representing the annual mean of `ds`.
"""
# Make a DataArray with the number of days in each month, size = len(time)
month_length = xray.DataArray(get_dpm(ds.time.to_index(),
calendar=calendar),
coords=[ds.time],
name='month_length')
# Calculate the weights by grouping by 'time.season'
weights = month_length / month_length.sum()
# Calculate the weighted average
return (ds * weights).sum(dim='time')
def test_vrtdiv():
path = ('/archive/Spencer.Hill/am2/am2clim_reyoi/gfdl.ncrc2-default-prod/'
'pp/atmos_level/ts/monthly/1yr/atmos_level.198301-198312.')
# Vertically defined, sigma levels.
u_arr = xray.open_dataset(path + 'ucomp.nc').ucomp
v_arr = xray.open_dataset(path + 'vcomp.nc').vcomp
vort, divg = compute_vrtdiv(u_arr, v_arr)
assert vort.shape == u_arr.shape
assert divg.shape == u_arr.shape
np.testing.assert_array_equal(u_arr.lat, vort.lat)
np.testing.assert_array_equal(u_arr.lon, vort.lon)
np.testing.assert_array_equal(u_arr.time, vort.time)
np.testing.assert_array_equal(u_arr.pfull, vort.pfull)
# Not vertically defined.
u0 = u_arr[:, 0]
v0 = v_arr[:, 0]
vort0, divg0 = compute_vrtdiv(u0, v0)
assert vort0.shape == u0.shape
assert divg0.shape == u0.shape
# Dummy case: zeros everywhere
u_arr_zeros = xray.DataArray(np.zeros_like(u_arr.values),
dims=u_arr.dims,
coords=u_arr.coords)
v_arr_zeros = u_arr_zeros.copy()
vort_zeros, divg_zeros = compute_vrtdiv(u_arr_zeros, v_arr_zeros)
assert not vort_zeros.any()
assert not divg_zeros.any()
def diff_z_to_zp1(self, array):
"""Take the vertical difference of an array located at z points, resulting
in a new array at zp1 points, but missing the upper and lower point.
Parameters
----------
array : xray DataArray
The array to difference. Must have the coordinate z.
Returns
-------
diff : xray DataArray
A new array with vertical coordinate zp1.
"""
a_up = array.isel(Z=slice(None, -1))
a_dn = array.isel(Z=slice(1, None))
a_diff = a_up.data - a_dn.data
# dimensions and coords of new array
coords, dims = self._get_coords_from_dims(array.dims,
replace={'Z': 'Zp1'})
# trim vertical
coords['Zp1'] = coords['Zp1'][1:-1]
return xray.DataArray(a_diff,
coords,
dims,
name=_append_to_name(array, 'diff_z_to_zp1'))
def __init__(self, fpa, ad_bit_depth, digital_gain=None, digital_offset=(0.0, 'count'), noise=(0.0, 'count'),
sitf=None, exp_time_min=(10.0e-6, 's'), exp_time_max=(np.inf, 's'), attrs=None):
""" Camera constructor. This class if for representation of a Camera, which incorporates
a FocalPlaneArray and a converter stage which converts photoelectrons into digital levels (also called
digital numbers - DN and in MORTICIA, the pint unit 'count' is used).
:param fpa: The FocalPlaneArray incorporated into the Camera
:param ad_bit_depth: Number of bits in the Analogue-to-Digital A/D converter. Must be provided in MORTICIA
scalar format as e.g. [16, 'bit']
:param digital_gain: The number of photoelectrons required to raise the output by 1 digital level (DN)
Must be provided in MORTICIA scalar format as e.g. [2.2, 'e/count'].
:param digital_offset: The digital level (DN) output of the camera for zero photoelectrons. This is not
the "black level", which typically includes additional dark signal. Must be provided in MORTICIA
scalar format as e.g. [10.0, 'count'].
:param noise: An optional additional noise component to add to the signal. Must be provided as a
MORTICIA scalar in either electrons or counts e.g. [2, 'e']. This is an RMS noise component,
which is equivalent to a standard deviation.
:param sitf: Signal transfer function (SiTF). As an alternative to providing the digital_gain and
digital_offset, (particularly should the camera have essentially non-linear response) the SiTF
can be provided as an xray.DataArray, with the input axis in units of electrons ('e') and
the data in units of digital level ('count'). If digital_gain and digital_offset are provided,
the SiTF is calculated and stored internally as an xray.DataArray.
:param
:param attrs: A user-defined dictionary of other information about this Camera object. Could include
items such as 'model', 'manufacturer' etc. A 'title' and 'long_name' are recommended attributes.
:return:
"""
self.fpa = fpa
self.ad_bit_depth = Scalar('bitdepth', *ad_bit_depth)
if digital_gain is not None:
self.digital_gain = Scalar('dgain', *digital_gain)
if sitf is not None:
warnings.warn('The digital_gain and the sitf of a Camera object should not both be provided.')
self.digital_offset = Scalar('doffset', *digital_offset) # Initialise
if sitf is not None: # Check and save the sitf
xd_check_convert_units(sitf, 'phe', default_units('phe'))
xd_check_convert_units(sitf, 'dn', default_units('dn'))
self.sitf = sitf
else: # Create an sitf from the digital gain and offet inputs
if digital_gain is None:
warnings.warn('Estimating Camera digital gain from bit depth and FPA well capacity')
self.digital_gain = Scalar('dgain', self.fpa.wellcapacity.data / 2.0**self.ad_bit_depth.data, 'e/count')
slope = 1.0 / self.digital_gain.data
# Compute the upper point of the sitf, taking A/D limit and well saturation into account
# Calculate digital numbers at the well capacity
dn_at_well_capacity = self.fpa.wellcapacity.data * slope + self.digital_offset.data
# Calculate the number of photelectrons at maximum DN
phe_at_max_dn = (2.0**self.ad_bit_depth.data - self.digital_offset.data) / slope
phe_max = np.minimum(phe_at_max_dn, self.fpa.wellcapacity.data) # Can't have more photoelectrons than well cap.
dn_max = np.minimum(dn_at_well_capacity, 2.0**self.ad_bit_depth.data) # Can't have more DN than 2^bits
self.sitf = xray.DataArray([self.digital_offset.data, dn_max],
[('phe', [0.0, phe_max], {'units': 'e', 'extrap_hi': 'sustain',
'extrap_lo': np.nan})],
name='dn', attrs={'units': 'count'})
if noise[1] == 'e': # Convert to dn count using the sitf
self.noise = Scalar('dnoise', noise[0] * slope, 'count')
else:
self.noise = Scalar('dnoise', *noise)
self.attrs = attrs # user-defined info about this camera
def pad_zl_to_zp1(self, array, fill_value=0., zlname='Zl', zp1name='Zp1'):
"""Pad an array located at zl points such that it is located at
zp1 points. An additional fill value is required for the bottom point.
Parameters
----------
array : xray DataArray
The array to difference. Must have the coordinate zp1.
fill_value : number, optional
The value to be used at the bottom point.
zlname : str, optional
The variable name for the zl point
zp1name : str, optional
The variable name for the zp1 point
Returns
-------
padded : xray DataArray
Padded array with vertical coordinate zp1.
"""
coords, dims = self._get_coords_from_dims(array.dims)
zdim = dims.index(zlname)
# shape of the new array to concat at the bottom
shape = list(array.shape)
shape[zdim] = 1
# replace Zl with the bottom level
coords[zlname] = np.atleast_1d(self.ds[zp1name][-1].data)
# an array of zeros at the bottom
# need different behavior for numpy vs dask
if array.chunks:
chunks = list(array.data.chunks)
chunks[zdim] = (1, )
zarr = fill_value * da.ones(
shape, dtype=array.dtype, chunks=chunks)
zeros = xray.DataArray(zarr, coords, dims).chunk()
else:
zarr = np.zeros(shape, array.dtype)
zeros = xray.DataArray(zarr, coords, dims)
newarray = xray.concat([array, zeros],
dim=zlname).rename({zlname: zp1name})
if newarray.chunks:
# this assumes that there was only one chunk in the vertical to begin with
# how can we do that better
return newarray.chunk({zp1name: len(newarray[zp1name])})
else:
return newarray
def construct_output_array(self, array, dims, coords):
out_array = xray.DataArray(array, dims=dims, coords=coords)
out_array.attrs['samplerate'] = self.time_series.attrs['samplerate']
if self.resamplerate > 0.0:
out_array.attrs['samplerate'] = self.time_series.attrs[
'samplerate']
return out_array
def running_mean(darray, window):
"""Calculate the running mean."""
dframe = darray.to_pandas()
dframe = pandas.rolling_mean(dframe, window, center=True)
dframe = dframe.dropna()
return xray.DataArray(dframe)
def test_unary(self):
args = [0,
np.zeros(2),
xray.Variable(['x'], [0, 0]),
xray.DataArray([0, 0], dims='x'),
xray.Dataset({'y': ('x', [0, 0])})]
for a in args:
self.assertIdentical(a + 1, xu.cos(a))
def __init__(self, treat_csv, notes, shape=((38, 14))):
self.shape = shape # plate format
self.treatments = pd.DataFrame.from_csv(treat_csv)
# row = treatment;
# columns = components;
# each item has tuple (quantity, units, start, stop)
self.map = xray.DataArray()
self.metadata = dict(notes)
def bwd_diff1(arr, dim, is_coord=False):
"""Backward differencing of the array. Not its full derivative."""
if is_coord:
arr_diff = arr[dim].diff(dim, n=1, label='upper')
return xray.DataArray(np.diff(arr[dim]),
dims=[dim],
coords=[arr_diff[dim]])
return arr.diff(dim, n=1, label='upper')
def create_time_array(self):
"""Create an xray.DataArray comprising the desired months."""
all_months = pd.date_range(start=self.apply_year_offset(
self.start_date),
end=self.apply_year_offset(self.end_date),
freq='M')
time = xray.DataArray(all_months, dims=[TIME_STR])
month_cond = self._construct_month_conditional(time, self.months)
return time[month_cond]
def coord_to_new_dataarray(arr, dim):
"""Create a DataArray comprising the coord for the specified dim.
Useful, for example, when wanting to resample in time, because at least
for xray 0.6.0 and prior, the `resample` method doesn't work when applied
to coords. The DataArray returned by this method lacks that limitation.
"""
return xray.DataArray(arr[dim].values,
coords=[arr[dim].values],
dims=[dim])
def test_invalid_dataarray_names_raise(self):
te = (TypeError, 'string or None')
ve = (ValueError, 'string must be length 1 or')
data = np.random.random((2, 2))
da = xray.DataArray(data)
for name, e in zip([0, (4, 5), True, ''], [te, te, te, ve]):
ds = Dataset({name: da})
with self.assertRaisesRegexp(*e):
with self.roundtrip(ds) as actual:
pass
def to_xray(self):
import xray
das = {}
for varname, unit in fields:
x, t, val = self.xtargs(varname)
das[varname] = xray.DataArray(val,
coords=(t, x),
dims=('time', 'x'))
return xray.Dataset(das)
def _initialize_array(global_grid, result_array):
"Fill in starting values for the energy array."
max_energies = global_grid['GM'].max(dim='points', skipna=False)
len_comps = result_array.dims['component']
if max_energies.isnull().any():
raise ValueError('Input energy surface contains one or more NaNs.')
result_array['GM'] = xray.broadcast_arrays(max_energies, result_array['GM'])[0].copy()
result_array['MU'] = xray.broadcast_arrays(max_energies, result_array['MU'])[0].copy()
result_array['MU'].values[:] = np.nan
result_array['NP'] = xray.broadcast_arrays(xray.DataArray(np.nan), result_array['NP'])[0].copy()
# Initial simplex for each target point in will be
# the fictitious hyperplane
# This hyperplane sits above the system's energy surface
# The reason for this is to guarantee our initial simplex contains
# the target point
# Note: We're assuming that the max energy is in the first few, presumably
# fictitious points instead of more rigorously checking with argmax.
result_array['points'] = xray.broadcast_arrays(xray.DataArray(np.arange(len_comps),
dims='vertex'),
result_array['points'])[0].copy()
def test_tend_each_timestep():
arr = load('ucomp')
darr_dt = tend_each_timestep(arr)
assert darr_dt.shape == arr.shape
np.testing.assert_array_equal(arr.time.values, darr_dt.time.values)
# Dummy case: zeros everywhere
arr_zeros = xray.DataArray(np.zeros_like(arr.values),
dims=arr.dims,
coords=arr.coords)
darr_dt = tend_each_timestep(arr_zeros)
assert not darr_dt.any()
def test_binary(self):
args = [0,
np.zeros(2),
xray.Variable(['x'], [0, 0]),
xray.DataArray([0, 0], dims='x'),
xray.Dataset({'y': ('x', [0, 0])})]
for n, t1 in enumerate(args):
for t2 in args[n:]:
self.assertIdentical(t2 + 1, xu.maximum(t1, t2 + 1))
self.assertIdentical(t2 + 1, xu.maximum(t2, t1 + 1))
self.assertIdentical(t2 + 1, xu.maximum(t1 + 1, t2))
self.assertIdentical(t2 + 1, xu.maximum(t2 + 1, t1))
def diff_xp1_to_x(self, array):
"""Difference DataArray ``array`` in the x direction.
Assumes that ``array`` is located at the xp1 point."""
left = array
right = self.roll(array, -1, "Xp1")
if array.chunks:
right = right.chunk(array.chunks)
diff = right.data - left.data
coords, dims = self._get_coords_from_dims(array.dims, replace={"Xp1": "X"})
return xray.DataArray(diff, coords, dims).rename(
_append_to_name(array, "diff_xp1_to_x")
)
def resampled(self,
resampled_rate,
window=None,
loop_axis=None,
num_mp_procs=0,
pad_to_pow2=False):
'''
:param resampled_rate: resample rate
:param window: ignored for now - added for legacy reasons
:param loop_axis: ignored for now - added for legacy reasons
:param num_mp_procs: ignored for now - added for legacy reasons
:param pad_to_pow2: ignored for now - added for legacy reasons
:return: resampled time series
'''
from scipy.signal import resample
samplerate = self.attrs['samplerate']
time_axis = self['time']
time_axis_length = np.squeeze(time_axis.shape)
new_length = int(
np.round(time_axis_length * resampled_rate / float(samplerate)))
# print new_length
# if self.time_axis_index<0:
# self.time_axis_index = get_axis_index(data_array=self, axis_name='time')
# time_axis = self.coords[ self.dims[self.time_axis_index] ]
# time_axis = self['time']
resampled_array, new_time_axis = resample(self.values,
new_length,
t=time_axis.values,
axis=self.time_axis_index,
window=window)
# print new_time_axis
#constructing axes
coords = []
for i, dim_name in enumerate(self.dims):
if i != self.time_axis_index:
coords.append(self.coords[dim_name].copy())
else:
coords.append((dim_name, new_time_axis))
resampled_time_series = xray.DataArray(resampled_array, coords=coords)
resampled_time_series.attrs['samplerate'] = resampled_rate
return resampled_time_series
def diff_yp1_to_y(self, array):
"""Difference DataArray ``array`` in the y direction.
Assumes that ``array`` is located at the yp1 point."""
left = array
right = self.roll(array, -1, 'Yp1')
if array.chunks:
right = right.chunk(array.chunks)
diff = right.data - left.data
coords, dims = self._get_coords_from_dims(array.dims,
replace={'Yp1': 'Y'})
return xray.DataArray(diff, coords, dims).rename(
_append_to_name(array, '_diff_yp1_to_y'))
def fwd_diff1(arr, dim, is_coord=False):
"""Forward differencing of the array. Not its full derivative.
A bug in xray version 0.6.1 and prior causes the `DataArray.diff`
method to not work when applied to a coordinate array. Therefore,
a workaround is implemented here and used if the `is_coord` keyword
argument is True.
"""
if is_coord:
arr_diff = arr[dim].diff(dim, n=1, label='lower')
return xray.DataArray(np.diff(arr[dim]),
dims=[dim],
coords=[arr_diff[dim]])
return arr.diff(dim, n=1, label='lower')
