def from_string(prjs):
"""Turn a PROJ.4 string into a mapping of parameters.
Bare parameters like "+no_defs" are given a value of ``True``. All keys
are checked against the ``all_proj_keys`` list.
EPSG:nnnn is allowed.
JSON text-encoded strings are allowed.
"""
if '{' in prjs:
# may be json, try to decode it
try:
val = json.loads(prjs, strict=False)
except ValueError:
raise CRSError('crs appears to be JSON but is not valid')
if not val:
raise CRSError("crs is empty JSON")
else:
return val
if prjs.strip().upper().startswith('EPSG:'):
return from_epsg(prjs.split(':')[1])
parts = [o.lstrip('+') for o in prjs.strip().split()]
def parse(v):
if v in ('True', 'true'):
return True
elif v in ('False', 'false'):
return False
else:
try:
return int(v)
except ValueError:
pass
try:
return float(v)
except ValueError:
return v
items = map(
lambda kv: len(kv) == 2 and (kv[0], parse(kv[1])) or (kv[0], True),
(p.split('=') for p in parts))
out = dict((k, v) for k, v in items if k in all_proj_keys)
if not out:
raise CRSError("crs is empty or invalid: {}".format(prjs))
return out
def from_string(cls, string, morph_from_esri_dialect=False):
"""Make a CRS from an EPSG, PROJ, or WKT string
Parameters
----------
string : str
An EPSG, PROJ, or WKT string.
morph_from_esri_dialect : bool, optional
If True, items in the input using Esri's dialect of WKT
will be replaced by OGC standard equivalents.
Returns
-------
CRS
"""
try:
string = string.strip()
except AttributeError:
pass
if not string:
raise CRSError("CRS is empty or invalid: {!r}".format(string))
elif string.upper().startswith('EPSG:'):
auth, val = string.split(':')
if not val:
raise CRSError("Invalid CRS: {!r}".format(string))
return cls.from_epsg(val)
elif string.startswith('{') or string.startswith('['):
# may be json, try to decode it
try:
val = json.loads(string, strict=False)
except ValueError:
raise CRSError('CRS appears to be JSON but is not valid')
if not val:
raise CRSError("CRS is empty JSON")
else:
return cls.from_dict(**val)
elif string.endswith("]"):
return cls.from_wkt(
string, morph_from_esri_dialect=morph_from_esri_dialect)
elif "=" in string:
return cls.from_proj4(string)
obj = cls()
obj._crs = _CRS.from_user_input(
string, morph_from_esri_dialect=morph_from_esri_dialect)
return obj
def from_user_input(cls, value, morph_from_esri_dialect=False):
"""Make a CRS from various input
Dispatches to from_epsg, from_proj, or from_string
Parameters
----------
value : obj
A Python int, dict, or str.
morph_from_esri_dialect : bool, optional
If True, items in the input using Esri's dialect of WKT
will be replaced by OGC standard equivalents.
Returns
-------
CRS
"""
if isinstance(value, cls):
return value
elif hasattr(value, "to_wkt") and callable(value.to_wkt):
return cls.from_wkt(
value.to_wkt(),
morph_from_esri_dialect=morph_from_esri_dialect,
)
elif isinstance(value, int):
return cls.from_epsg(value)
elif isinstance(value, dict):
return cls(**value)
elif isinstance(value, string_types):
return cls.from_string(
value, morph_from_esri_dialect=morph_from_esri_dialect)
else:
raise CRSError("CRS is invalid: {!r}".format(value))
def to_dict(self, projjson=False):
"""Convert CRS to a PROJ dict
.. note:: If there is a corresponding EPSG code, it will be used
when returning PROJ parameter dict.
.. versionadded:: 1.3.0
Parameters
----------
projjson: bool, default=False
If True, will convert to PROJ JSON dict (Requites GDAL 3.1+
and PROJ 6.2+). If False, will convert to PROJ parameter
dict.
Returns
-------
dict
"""
if self._crs is None:
raise CRSError("Undefined CRS has no dict representation")
if projjson:
text = self._crs.projjson()
return json.loads(text) if text else {}
epsg_code = self.to_epsg()
if epsg_code:
return {'init': 'epsg:{}'.format(epsg_code)}
else:
try:
return self._crs.to_dict()
except CRSError:
return {}
def from_any(cls, proj: dict or str or int):
"""
Makes CRS from any supported system
Parameters
----------
proj: dict or str or int
Projection in PROJ, EPSG, WKT or CF.
Returns
-------
CRS: XCRS
"""
if isinstance(proj, dict):
try:
return cls.from_dict(proj)
except CRSError:
return cls.from_cf_dict(proj)
except Exception:
raise CRSError("{} is neither a PROJ4 or CF dict".format(proj))
elif isinstance(proj, str):
for method in ['from_string', 'from_proj4', 'from_wkt']:
try:
return getattr(cls, method)(proj)
except CRSError:
pass
raise CRSError(
"{} is neither a EPSG, PROJ4 or WKT string".format(proj))
elif isinstance(proj, int):
try:
return cls.from_epsg(proj)
except CRSError:
raise CRSError("{} is not valid EPSG code".format(proj))
elif isinstance(proj, cls):
return proj
else:
raise IOError(
"{} is not valid data type. Only dictionary, string or integer are supported"
.format(proj))
def _to_crs_str(value):
# After rasterio=1.0.14 WKT is backbone so try it first
try:
crs_ = CRS.from_wkt(value)
crs_.is_valid
except CRSError as err:
logger.debug('Could not parse CRS as WKT', err)
try:
crs_ = CRS.from_string(value)
crs_.is_valid
except CRSError as err:
logger.debug('Could not parse CRS as Proj4', err)
raise CRSError('Could not interpret CRS input as '
'either WKT or Proj4')
return crs_
def _parse_crs(crs):
"""Parse a coordinate reference system from a variety of representations.
Parameters
----------
crs : {str, dict, int, CRS}
Must be either a rasterio CRS object, a proj-string, rasterio supported
dictionary, WKT string, or EPSG integer.
Returns
-------
rasterio.crs.CRS
The parsed CRS.
Raises
------
CRSError
Raises an error if the input cannot be parsed.
"""
#
# NOTE: This doesn't currently throw an error if the EPSG code is invalid.
#
parsed = None
if isinstance(crs, CRS):
parsed = crs
elif isinstance(crs, str):
try:
# proj-string or wkt
parsed = CRS.from_string(crs)
except CRSError:
# wkt
parsed = CRS.from_wkt(crs)
elif isinstance(crs, dict):
parsed = CRS(crs)
elif isinstance(crs, int):
parsed = CRS.from_epsg(crs)
elif isinstance(crs, pyproj.Proj):
parsed = CRS.from_proj4(crs.proj4_init)
if parsed is None or not parsed.is_valid:
raise CRSError('Could not parse CRS: {}'.format(crs))
return parsed
def reproject(self, dst_crs):
"""
Reprojects all the features to the new crs
Args:
dst_crs: rasterio.CRS or any acceptable by your rasterio version input (str, dict, epsg code), ot 'utm'
Returns:
new reprojected FeatureCollection
"""
if isinstance(dst_crs, str) and dst_crs == 'utm':
lon1, lat1, lon2, lat2 = self.index.bounds
dst_crs = _utm_zone((lat1 + lat2)/2, (lon1 + lon2)/2)
else:
dst_crs = dst_crs if isinstance(dst_crs, CRS) else CRS.from_user_input(dst_crs)
# Old rasterio compatibility: a separate check for validity
if not dst_crs.is_valid:
raise CRSError('Invalid CRS {} given'.format(dst_crs))
features = [f.reproject(dst_crs) for f in self.features]
return FeatureCollection(features, dst_crs)
def get_extent(ds):
"""Extract the extent (bounding box) from the dataset.
Parameters
----------
ds : xarray.Dataset
The input dataset
Returns
-------
tuple
The extent (left, bottom, right, top) in latitude and longitude
coordinates.
"""
#
# Check if latitude and longitude are stored as coordinates.
#
if 'lon' in ds.coords and 'lat' in ds.coords:
return BoundingBox(left=ds.lon.values.min(),
bottom=ds.lat.values.min(),
right=ds.lon.values.max(),
top=ds.lat.values.max())
#
# Otherwise, get extent from projection information
# by projecting the corner coordinates onto EPSG:4326
# to obtain the latitude and longitude at the four corners.
#
src_crs = get_crs(ds)
if src_crs is None:
raise CRSError('Could not determine the CRS.')
dst_crs = CRS(init='epsg:4326')
proj_bounds = get_bounds(ds)
bounds = rasterio.warp.transform_bounds(src_crs, dst_crs,
**proj_bounds._asdict())
return BoundingBox(*bounds)
def to_dict(self):
"""Convert CRS to a PROJ4 dict
Notes
-----
If there is a corresponding EPSG code, it will be used.
Returns
-------
dict
"""
if self._crs is None:
raise CRSError("Undefined CRS has no dict representation")
else:
epsg_code = self.to_epsg()
if epsg_code:
return {'init': 'epsg:{}'.format(epsg_code)}
else:
try:
return self._crs.to_dict()
except CRSError:
return {}
def _reproject(ds,
src_crs=None,
dst_crs=None,
dst_transform=None,
width=None,
height=None,
res=None,
extent=None,
**kwargs):
"""Reproject a Dataset or DataArray.
Parameters
----------
ds : xarray.Dataset or xarray.DataArray
The input dataset
src_crs : CRS-like, optional
An object that can be parsed into a CRS. By default, try to infer from
input dataset.
dst_crs : CRS-like, optional
An object that can be parsed into a CRS. By default, use the same
CRS as the input dataset.
dst_transform : affine.Affine, optional
The geometric transform of the output dataset.
width : int, optional
The width of the output dataset.
height : int, optional
The height of the output dataset.
res : tuple (float, float), optional
The resolution of the output dataset.
extent : tuple, optional
The output extent. By default this is determined from the input data.
**kwargs : dict, optional
Extra keyword arguments for ``rasterio.warp.reproject``.
Returns
-------
xarray.Dataset or xarray.DataArray
The projected dataset.
"""
if src_crs is None:
src_crs = get_crs(ds)
if src_crs is None:
raise CRSError('Could not infer projection from input data. '
'Please provide the parameter `src_crs`.')
src_bounds = get_bounds(ds)
if extent is not None:
extent = BoundingBox(*extent)
#
# Only allow inferring of width or height from aspect ratio
# if the CRS is not changed.
#
if dst_crs is None:
dst_crs = src_crs
if width is None and height is not None:
width = int(ncols(ds) * height / nrows(ds))
elif height is None and width is not None:
height = int(nrows(ds) * width / ncols(ds))
# Given: transform, shape
# Given: transform, extent
# Given: res, extent
# Given: shape, res
# Given: shape, extent
if dst_transform is not None:
#
# If the transform is given, we also need the width and height or
# the extent.
#
if width is not None and height is not None:
pass
elif extent is not None:
# Calculate width and height from extent
width = int(abs(
(extent.right - extent.left) / dst_transform.a)) + 1
height = int(abs(
(extent.top - extent.bottom) / dst_transform.e)) + 1
else:
raise ValueError('Not enough information provided.')
elif extent is not None:
#
# Transform can be calculated from extent, if either width and height
# or the resolution are given.
#
if res is not None:
width = int(abs((extent.right - extent.left) / res[0])) + 1
height = int(abs((extent.top - extent.bottom) / res[1])) + 1
# The following doesn't give the correct result.
dst_transform = rasterio.transform.from_bounds(*extent,
width=width - 1,
height=height - 1)
else:
#
# If neither the transform nor the extent are given, infer the best
# possible parameters from the width, height, and the resolution.
#
dst_transform, width, height = \
rasterio.warp.calculate_default_transform(
src_crs, dst_crs,
ncols(ds), nrows(ds),
resolution=res,
dst_width=width,
dst_height=height,
**src_bounds._asdict())
src_transform = get_transform(ds)
src_dims = get_dims(ds)
dst_crs = _parse_crs(dst_crs)
#
# Prepare new x and y coordinate arrays
#
dst_x, _ = dst_transform * (np.arange(width), np.zeros(width, dtype=int))
_, dst_y = dst_transform * (np.zeros(height, dtype=int), np.arange(height))
dst_coords = {'x': dst_x, 'y': dst_y}
#
# Handle the case where there are extra dimensions, e.g. 'time'
# or 'band'
#
extra_dims = set(src_dims) - {'y', 'x'}
for c in extra_dims:
dst_coords[c] = ds.coords[c]
def _reproject_da(da, shape):
#
# Reproject a single data array
#
coord_dims = tuple(c for c in ('y', 'x') if c in da.dims)
extra_dims = set(da.dims) - set(coord_dims)
# Preserve original dimension order
orig_dim_order = get_dims(da)
ordered_extra_dims = \
tuple(d for d in orig_dim_order if d in extra_dims)
dim_order = ordered_extra_dims + coord_dims
# Determine best resampling method from data type
if np.issubdtype(da.dtype, np.integer):
nodata = 0
default_resampling = rasterio.warp.Resampling.nearest
else:
nodata = np.nan
default_resampling = rasterio.warp.Resampling.bilinear
if 'resampling' not in kwargs:
kwargs['resampling'] = default_resampling
# Get values as numpy array such that last two axes are
# y and x
values = da.transpose(*dim_order, transpose_coords=True).values
# Flatten multidimensional data to ONE extra dimension
if values.ndim > 2:
output_shape = values.shape[:-2] + shape
values = values.reshape((-1, ) + values.shape[-2:])
output_shape_flat = (values.shape[0], ) + shape
else:
output_shape = shape
output_shape_flat = shape
# rasterio cannot deal with float16
if da.dtype == np.float16:
values = values.astype(np.float32)
# Integers cannot be set to nan
if np.issubdtype(values.dtype, np.integer):
values = values.astype(np.float32)
output = np.zeros(output_shape_flat, dtype=values.dtype)
output[:] = np.nan
rasterio.warp.reproject(values,
output,
src_transform=src_transform,
src_crs=src_crs,
dst_transform=dst_transform,
dst_crs=dst_crs,
dst_nodata=nodata,
**kwargs)
if da.dtype == np.float16:
output = output.astype(np.float16)
# Final reshape in case the input was one-dimensional
return output.reshape(output_shape)
if isinstance(ds, xr.Dataset):
result = xr.Dataset(coords=dst_coords)
#
# Also reproject coordinate arrays that are defined over
# x and y
#
for v in ds.coords:
#
# If the projection is the same (i.e. resampling),
# also reproject coordinate arrays
# that are defined over only one variable.
#
if dst_crs == src_crs and v not in ds.dims:
if len(ds.coords[v].dims) == 0:
result.coords[v] = (ds.coords[v].dims, ds.coords[v].data)
else:
expanded = _expand_var_to_xy(ds.coords[v], ds.coords)
if ds.coords[v].dims == ('x', ):
result.coords[v] = (('y', 'x'),
_reproject_da(
expanded, (height, width)))
elif ds.coords[v].dims == ('y', ):
result.coords[v] = (('y', 'x'),
_reproject_da(
expanded, (height, width)))
# Remove redundant dimensions
coords = _collapse_coords(result.coords[v])
result.coords[v] = (coords.dims, coords)
if not set(ds.coords[v].dims).issuperset({'x', 'y'}):
continue
shape = (height, width)
result.coords[v] = (('y', 'x'), _reproject_da(ds.coords[v], shape))
#
# Reproject the actual data
#
for v in ds.data_vars:
vdims = _get_projection_dim_order(ds[v])
common = set(vdims).intersection(ds[v].dims)
shape = (height, width)
if set(ds[v].dims) == set(vdims) or set(ds[v].dims) == {'y', 'x'}:
result[v] = (vdims, _reproject_da(ds[v], shape))
# Reorder dimensions of each variable to match original.
result[v] = result[v].transpose(*get_dims(ds[v]),
transpose_coords=True)
elif common == {'x'} or common == {'y'}:
# Does the data contain either x or y dimension?
# Expand to grid and then reproject as two dimensional.
result[v] = (vdims,
_reproject_da(_expand_var_to_xy(ds[v], ds.coords),
shape))
else:
# The variable doesn't contain either y or x dimension.
result[v] = (ds[v].dims, ds[v].data)
#
# Create lat and lon coordinates
#
# if 'lat' in ds.coords and 'lon' in ds.coords:
# lon, lat = rasterio.warp.transform(
# src_crs, dst_crs, ds.coords['x'], ds.coords['y'])
# result.coords['lon'] = (('x',), lon)
# result.coords['lat'] = (('y',), lat)
elif isinstance(ds, xr.DataArray):
shape = (height, width)
dst_dims = _get_projection_dim_order(ds)
result = xr.DataArray(_reproject_da(ds, shape),
dims=dst_dims,
coords=dst_coords,
name=ds.name)
# Reorder dimensions to match original.
result = result.transpose(*get_dims(ds), transpose_coords=True)
#
# Add metadata
#
result.attrs = ds.attrs
# Serialize transform to tuple and store in metadata
result.attrs['transform'] = dst_transform[:6]
# Store CRS info in metadata
result.attrs['crs'] = dst_crs.to_string()
result.attrs['coordinate_system_string'] = dst_crs.wkt
# Store new data shape in metadata
result.attrs['lines'] = nrows(result)
result.attrs['samples'] = ncols(result)
_add_latlon(result)
return result
