from __future__ import (absolute_import, division, print_function)

from collections import OrderedDict

import numpy as np

from .util import extract_vars, get_id, get_iterable, is_mapping, to_np

from .py3compat import viewkeys

from .latlonutils import _lat_varname, _lon_varname, _ll_to_xy, _xy_to_ll

from .metadecorators import set_latlon_metadata

from .constants import Constants, ProjectionTypes

from .config import xarray_enabled

if xarray_enabled():

from xarray import DataArray

def get_lat(wrfin, timeidx=0, method="cat", squeeze=True,

cache=None, meta=True, _key=None,

stagger=None):

"""Return the two dimensional latitude coordinate variable.

This functions extracts the necessary variables from the NetCDF file

object in order to perform the calculation.

Args:

wrfin (:class:`netCDF4.Dataset`, :class:`Nio.NioFile`, or an \

iterable): WRF-ARW NetCDF

data as a :class:`netCDF4.Dataset`, :class:`Nio.NioFile`

or an iterable sequence of the aforementioned types.

timeidx (:obj:`int` or :data:`wrf.ALL_TIMES`, optional): The

desired time index. This value can be a positive integer,

negative integer, or

:data:`wrf.ALL_TIMES` (an alias for None) to return

all times in the file or sequence. The default is 0.

method (:obj:`str`, optional): The aggregation method to use for

sequences. Must be either 'cat' or 'join'.

'cat' combines the data along the Time dimension.

'join' creates a new dimension for the file index.

The default is 'cat'.

squeeze (:obj:`bool`, optional): Set to False to prevent dimensions

with a size of 1 from being automatically removed from the shape

of the output. Default is True.

cache (:obj:`dict`, optional): A dictionary of (varname, ndarray)

that can be used to supply pre-extracted NetCDF variables to the

computational routines. It is primarily used for internal

purposes, but can also be used to improve performance by

eliminating the need to repeatedly extract the same variables

used in multiple diagnostics calculations, particularly when using

large sequences of files.

Default is None.

meta (:obj:`bool`, optional): Set to False to disable metadata and

return :class:`numpy.ndarray` instead of

:class:`xarray.DataArray`. Default is True.

_key (:obj:`int`, optional): A caching key. This is used for internal

purposes only. Default is None.

stagger (:obj:`str`): By default, the latitude is returned on the mass

grid, but a staggered grid can be chosen with the following

options:

- 'm': Use the mass grid (default).

- 'u': Use the same staggered grid as the u wind component,

which has a staggered west_east (x) dimension.

- 'v': Use the same staggered grid as the v wind component,

which has a staggered south_north (y) dimension.

Returns:

:class:`xarray.DataArray` or :class:`numpy.ndarray`: The

two dimensional latitude coordinate variable.

If xarray is enabled and the *meta* parameter is True, then the result

will be a :class:`xarray.DataArray` object. Otherwise, the result will

be a :class:`numpy.ndarray` object with no metadata.

"""

varname = _lat_varname(wrfin, stagger)

lat_var = extract_vars(wrfin, timeidx, varname, method, squeeze, cache,

meta, _key)

return lat_var[varname]

def get_lon(wrfin, timeidx=0, method="cat", squeeze=True,

cache=None, meta=True, _key=None,

stagger=None):

"""Return the two dimensional longitude coordinate variable.

This functions extracts the necessary variables from the NetCDF file

object in order to perform the calculation.

Args:

wrfin (:class:`netCDF4.Dataset`, :class:`Nio.NioFile`, or an \

iterable): WRF-ARW NetCDF

data as a :class:`netCDF4.Dataset`, :class:`Nio.NioFile`

or an iterable sequence of the aforementioned types.

timeidx (:obj:`int` or :data:`wrf.ALL_TIMES`, optional): The

desired time index. This value can be a positive integer,

negative integer, or

:data:`wrf.ALL_TIMES` (an alias for None) to return

all times in the file or sequence. The default is 0.

method (:obj:`str`, optional): The aggregation method to use for

sequences. Must be either 'cat' or 'join'.

'cat' combines the data along the Time dimension.

'join' creates a new dimension for the file index.

The default is 'cat'.

squeeze (:obj:`bool`, optional): Set to False to prevent dimensions

with a size of 1 from being automatically removed from the shape

of the output. Default is True.

cache (:obj:`dict`, optional): A dictionary of (varname, ndarray)

that can be used to supply pre-extracted NetCDF variables to the

computational routines. It is primarily used for internal

purposes, but can also be used to improve performance by

eliminating the need to repeatedly extract the same variables

used in multiple diagnostics calculations, particularly when using

large sequences of files.

Default is None.

meta (:obj:`bool`, optional): Set to False to disable metadata and

return :class:`numpy.ndarray` instead of

:class:`xarray.DataArray`. Default is True.

_key (:obj:`int`, optional): A caching key. This is used for internal

purposes only. Default is None.

stagger (:obj:`str`): By default, the longitude is returned on the mass

grid, but a staggered grid can be chosen with the following

options:

- 'm': Use the mass grid (default).

- 'u': Use the same staggered grid as the u wind component,

which has a staggered west_east (x) dimension.

- 'v': Use the same staggered grid as the v wind component,

which has a staggered south_north (y) dimension.

Returns:

:class:`xarray.DataArray` or :class:`numpy.ndarray`: The

two dimensional longitude coordinate variable.

If xarray is enabled and the *meta* parameter is True, then the result

will be a :class:`xarray.DataArray` object. Otherwise, the result will

be a :class:`numpy.ndarray` object with no metadata.

"""

varname = _lon_varname(wrfin, stagger)

lon_var = extract_vars(wrfin, timeidx, varname, method, squeeze, cache,

meta, _key)

return lon_var[varname]

def _llxy_mapping(wrfin, x_or_lat, y_or_lon, func, timeidx, stagger,

squeeze, meta, as_int=None):

"""Return the x,y/lat,lon coordinates for a dictionary input.

The leftmost dimension(s) for the result is:

- return_val[key,...,0,...] will contain the x/lat values.

- return_val[key,...,1,...] will contain the y/lon values.

Nested dictionaries are allowed.

Args:

wrfin (:obj:`dict`): A mapping of key name to a WRF NetCDF file object

or sequence of WRF NetCDF file objects.

x_or_lat (:obj:`float` or sequence): A single latitude/x value or a

sequence of latitude/x values to be converted.

y_or_lon (:obj:`float` or sequence): A single longitude/y value or a

sequence of longitude/y values to be converted.

func (function): Either the xy_to_ll or ll_to_xy function.

timeidx (:obj:`int` or :data:`wrf.ALL_TIMES`): The

desired time index. This value can be a positive integer,

negative integer, or

:data:`wrf.ALL_TIMES` (an alias for None) to return

all times in the file or sequence. The default is 0.

stagger (:obj:`str`): By default, the values are returned on the mass

grid, but a staggered grid can be chosen with the following

options:

- 'm': Use the mass grid (default).

- 'u': Use the same staggered grid as the u wind component,

which has a staggered west_east (x) dimension.

- 'v': Use the same staggered grid as the v wind component,

which has a staggered south_north (y) dimension.

squeeze (:obj:`bool`, optional): Set to False to prevent dimensions

with a size of 1 from being automatically removed from the shape

of the output. Default is True.

meta (:obj:`bool`, optional): Set to False to disable metadata and

return :class:`numpy.ndarray` instead of

:class:`xarray.DataArray`. Default is True.

as_int (:obj:`bool`, optional): Set to True to return the x,y values as

:obj:`int`, otherwise they will be returned as :obj:`float`. This

is only used when *func* is ll_to_xy.

Returns:

:class:`xarray.DataArray` or :class:`numpy.ndarray`: The

lat,lon/x,y coordinate value(s) whose leftmost dimensions are the

dictionary keys, followed by a dimension of size

2 (0=X, 1=Y)/(0=lat, 1=lon).

If xarray is enabled and the *meta* parameter is True, then the result

will be a :class:`xarray.DataArray` object. Otherwise, the result will

be a :class:`numpy.ndarray` object with no metadata.

"""

keynames = []

# This might not work once mapping iterators are implemented

numkeys = len(wrfin)

key_iter = iter(viewkeys(wrfin))

first_key = next(key_iter)

keynames.append(first_key)

first_args = [wrfin[first_key], x_or_lat, y_or_lon, timeidx, squeeze,

meta, stagger]

if as_int is not None:

first_args.append(as_int)

first_array = func(*first_args)

# Create the output data numpy array based on the first array

outdims = [numkeys]

outdims += first_array.shape

outdata = np.empty(outdims, first_array.dtype)

outdata[0, :] = first_array[:]

idx = 1

while True:

try:

key = next(key_iter)

except StopIteration:

break

else:

keynames.append(key)

args = [wrfin[first_key], x_or_lat, y_or_lon, timeidx, squeeze,

meta, stagger]

if as_int is not None:

args.append(as_int)

result_array = func(*args)

if outdata.shape[1:] != result_array.shape:

raise ValueError("data sequences must have the "

"same size for all dictionary keys")

outdata[idx, :] = to_np(result_array)[:]

idx += 1

if xarray_enabled() and meta:

outname = str(first_array.name)

# Note: assumes that all entries in dict have same coords

outcoords = OrderedDict(first_array.coords)

# First find and store all the existing key coord names/values

# This is applicable only if there are nested dictionaries.

key_coordnames = []

coord_vals = []

existing_cnt = 0

while True:

key_coord_name = "key_{}".format(existing_cnt)

if key_coord_name not in first_array.dims:

break

key_coordnames.append(key_coord_name)

coord_vals.append(to_np(first_array.coords[key_coord_name]))

existing_cnt += 1

# Now add the key coord name and values for THIS dictionary.

# Put the new key_n name at the bottom, but the new values will

# be at the top to be associated with key_0 (left most). This

# effectively shifts the existing 'key_n' coordinate values to the

# right one dimension so *this* dicionary's key coordinate values

# are at 'key_0'.

key_coordnames.append(key_coord_name)

coord_vals.insert(0, keynames)

# make it so that key_0 is leftmost

outdims = key_coordnames + list(first_array.dims[existing_cnt:])

# Create the new 'key_n', value pairs

for coordname, coordval in zip(key_coordnames, coord_vals):

outcoords[coordname] = coordval

outattrs = OrderedDict(first_array.attrs)

outarr = DataArray(outdata, name=outname, coords=outcoords,

dims=outdims, attrs=outattrs)

else:

outarr = outdata

return outarr

@set_latlon_metadata(xy=True)

def ll_to_xy(wrfin, latitude, longitude, timeidx=0,

squeeze=True, meta=True, stagger=None, as_int=True):

"""Return the x,y coordinates for a specified latitude and longitude.

The *latitude* and *longitude* arguments can be a single value or a

sequence of values.

The leftmost dimension of the returned array represents two different

quantities:

- return_val[0,...] will contain the X (west_east) values.

- return_val[1,...] will contain the Y (south_north) values.

Args:

wrfin (:class:`netCDF4.Dataset`, :class:`Nio.NioFile`, or an \

iterable): WRF-ARW NetCDF

data as a :class:`netCDF4.Dataset`, :class:`Nio.NioFile`

or an iterable sequence of the aforementioned types.

latitude (:obj:`float` or sequence): A single latitude or a sequence

of latitude values to be converted.

longitude (:obj:`float` or sequence): A single longitude or a sequence

of latitude values to be converted.

timeidx (:obj:`int` or :data:`wrf.ALL_TIMES`, optional): The

desired time index. This value can be a positive integer,

negative integer, or

:data:`wrf.ALL_TIMES` (an alias for None) to return

all times in the file or sequence. The default is 0.

squeeze (:obj:`bool`, optional): Set to False to prevent dimensions

with a size of 1 from being automatically removed from the shape

of the output. Default is True.

meta (:obj:`bool`, optional): Set to False to disable metadata and

return :class:`numpy.ndarray` instead of

:class:`xarray.DataArray`. Default is True.

stagger (:obj:`str`): By default, the latitude is returned on the mass

grid, but a staggered grid can be chosen with the following

options:

- 'm': Use the mass grid (default).

- 'u': Use the same staggered grid as the u wind component,

which has a staggered west_east (x) dimension.

- 'v': Use the same staggered grid as the v wind component,

which has a staggered south_north (y) dimension.

as_int (:obj:`bool`): Set to False to return the x,y values as

:obj:`float`, otherwise they will be returned as :obj:`int`.

Returns:

:class:`xarray.DataArray` or :class:`numpy.ndarray`: The

x,y coordinate value(s) whose leftmost dimension is 2 (0=X, 1=Y).

If xarray is enabled and the *meta* parameter is True, then the result

will be a :class:`xarray.DataArray` object. Otherwise, the result will

be a :class:`numpy.ndarray` object with no metadata.

"""

if is_mapping(wrfin):

return _llxy_mapping(wrfin, latitude, longitude, ll_to_xy,

timeidx, stagger, squeeze, meta, as_int)

_key = get_id(wrfin)

_wrfin = get_iterable(wrfin)

return _ll_to_xy(latitude, longitude, _wrfin, timeidx, stagger, "cat",

squeeze, None, _key, as_int, **{})

def _set_defaults(projparams):

"""Check projection parameters and set defaults.

Throws an exception if projection parameters required by WPS are not

provided, along with any other parameters required by the map projection

transformation routines.

For parameters not used by the projection type, defaults are used so that

the None values don't pass through to fortran downstream.

Args:

projparams (:obj:`dict`): Projection parameters dictionary.

Returns:

:obj:`dict`: The projection parameters with default values inserted

where applicable.

"""

_params = dict(projparams)

map_proj = _params.get("map_proj")

# All projections require these arguments

if map_proj is None:

raise ValueError("'map_proj' cannot be None")

if _params.get("ref_lat") is None:

raise ValueError("'ref_lat' cannot be None")

if _params.get("ref_lon") is None:

raise ValueError("'ref_lon' cannot be None")

if _params.get("known_x") is None:

raise ValueError("'known_x' cannot be None")

if _params.get("known_y") is None:

raise ValueError("'known_y' cannot be None")

if _params.get("dx") is None:

raise ValueError("'dx' cannot be None")

# Requires truelat1,stand_lon, truelat2, dx, dy

if map_proj == ProjectionTypes.LAMBERT_CONFORMAL:

if _params.get("truelat1") is None:

raise ValueError("'truelat1' cannot be None")

if _params.get("stand_lon") is None:

raise ValueError("'stand_lon' cannot be None")

if _params.get("truelat2") is None:

_params["truelat2"] = _params["truelat1"]

# Requires truelat1, stand_lon

elif map_proj == ProjectionTypes.POLAR_STEREOGRAPHIC:

if _params.get("truelat1") is None:

raise ValueError("'truelat1' cannot be None")

if _params.get("stand_lon") is None:

raise ValueError("'stand_lon' cannot be None")

# Requires truelat1

elif map_proj == ProjectionTypes.MERCATOR:

if _params.get("truelat1") is None:

raise ValueError("'truelat1' cannot be None")

if _params.get("stand_lon") is None:

_params["stand_lon"] = 0.0

# Requires pole_lat, pole_lon, stand_lon

elif map_proj == ProjectionTypes.LAT_LON:

if _params.get("stand_lon") is None:

raise ValueError("'stand_lon' cannot be None")

if _params.get("dy") is None:

raise ValueError("'dy' cannot be None")

if _params.get("pole_lat") is None:

raise ValueError("'pole_lat' cannot be None")

if _params.get("pole_lon") is None:

raise ValueError("'pole_lon' cannot be None")

if _params.get("latinc") is None:

_params["latinc"] = ((_params["dy"]*360.0)/2.0 /

Constants.PI/Constants.WRF_EARTH_RADIUS)

if _params.get("loninc") is None:

_params["loninc"] = ((_params["dx"]*360.0)/2.0 /

Constants.PI/Constants.WRF_EARTH_RADIUS)

else:

raise ValueError("invalid 'map_proj' value of {}".format(map_proj))

# Set these to defaults if not used so that the Fortran routines

# don't crash

if _params.get("truelat1") is None:

_params["truelat1"] = 0.

if _params.get("truelat2") is None:

_params["truelat2"] = 0.

if _params.get("pole_lat") is None:

_params["pole_lat"] = 90.0

if _params.get("pole_lon") is None:

_params["pole_lon"] = 0.0

if _params.get("dx") is None:

_params["dx"] = 0.0

if _params.get("dy") is None:

_params["dy"] = 0.0

if _params.get("latinc") is None:

_params["latinc"] = 0.

if _params.get("loninc") is None:

_params["loninc"] = 0.

return _params

@set_latlon_metadata(xy=True)

def ll_to_xy_proj(latitude, longitude, meta=True, squeeze=True, as_int=True,

map_proj=None, truelat1=None, truelat2=None, stand_lon=None,

ref_lat=None, ref_lon=None, pole_lat=None, pole_lon=None,

known_x=None, known_y=None, dx=None, dy=None,

latinc=None, loninc=None):

"""Return the x, y coordinates for a specified latitude and longitude.

The *latitude* and *longitude* arguments can be a single value or a

sequence of values. This version of the ll_to_xy routine allows users

to manually specify projection parameters.

The leftmost dimension of the returned array represents two different

quantities:

- return_val[0,...] will contain the X (west_east) values.

- return_val[1,...] will contain the Y (south_north) values.

Args:

latitude (:obj:`float` or sequence): A single latitude or a sequence

of latitude values to be converted.

longitude (:obj:`float` or sequence): A single longitude or a sequence

of latitude values to be converted.

squeeze (:obj:`bool`, optional): Set to False to prevent dimensions

with a size of 1 from being automatically removed from the shape

of the output. Default is True.

meta (:obj:`bool`, optional): Set to False to disable metadata and

return :class:`numpy.ndarray` instead of

:class:`xarray.DataArray`. Default is True.

as_int (:obj:`bool`): Set to False to return the x,y values as

:obj:`float`, otherwise they will be returned as :obj:`int`.

Default is True.

map_proj (:obj:`int`): Model projection [1=Lambert Conformal,

2=Polar Stereographic, 3=Mercator, 6=Lat-Lon]. Required.

truelat1 (:obj:`float`): Latitude of true scale 1. Required for

map_proj = 1, 2, 3 (defaults to 0 otherwise).

truelat2 (:obj:`float`): Latitude of true scale 2. Optional for

map_proj = 1 (defaults to 0 otherwise).

stand_lon (:obj:`float`): Standard longitude. Required for *map_proj* =

1, 2, 6 (defaults to 0 otherwise).

ref_lat (:obj:`float`): A reference latitude. Required.

ref_lon (:obj:`float`): A reference longitude. Required.

known_x (:obj:`float`): The known x-coordinate associated with

*ref_lon*. Required.

known_y (:obj:`float`): The known y-coordinate associated with

*ref_lat*. Required.

pole_lat (:obj:`float`): Pole latitude. Required for

*map_proj* = 6 (use 90 for no rotation).

pole_lon (:obj:`float`): Pole longitude. Required for

*map_proj* = 6 (use 0 for no rotation).

dx (:obj:`float`): The x spacing in meters at the true latitude.

Required for all map projections.

dy (:obj:`float`) - The y spacing in meters at the true latitude.

Required for *map_proj* = 6 (defaults to 0 otherwise).

latinc (:obj:`float`): Optional for *map_proj* = 6. Default is:

.. code-block:: python

latinc = (dy*360.0)/2.0/Constants.PI/Constants.WRF_EARTH_RADIUS

loninc (:obj:`float`): Optional for *map_proj* = 6. Default is:

.. code-block:: python

loninc = (dx*360.0)/2.0/Constants.PI/Constants.WRF_EARTH_RADIUS

Returns:

:class:`xarray.DataArray` or :class:`numpy.ndarray`: The

x,y coordinate value(s) whose leftmost dimension is 2 (0=X, 1=Y).

If xarray is enabled and the *meta* parameter is True, then the result

will be a :class:`xarray.DataArray` object. Otherwise, the result will

be a :class:`numpy.ndarray` object with no metadata.

"""

loc = locals()

_projparams = {name: loc[name] for name in ("map_proj", "truelat1",

"truelat2", "stand_lon",

"ref_lat", "ref_lon",

"pole_lat", "pole_lon",

"known_x", "known_y", "dx",

"dy", "latinc", "loninc")}

projparams = _set_defaults(_projparams)

return _ll_to_xy(latitude, longitude, None, 0, True, "cat", squeeze, None,

None, as_int, **projparams)

@set_latlon_metadata(xy=False)

def xy_to_ll(wrfin, x, y, timeidx=0, squeeze=True, meta=True, stagger=None):

"""Return the latitude and longitude for specified x,y coordinates.

The *x* and *y* arguments can be a single value or a sequence of values.

The leftmost dimension of the returned array represents two different

quantities:

- return_val[0,...] will contain the latitude values.

- return_val[1,...] will contain the longitude values.

Args:

wrfin (:class:`netCDF4.Dataset`, :class:`Nio.NioFile`, or an \

iterable): WRF-ARW NetCDF

data as a :class:`netCDF4.Dataset`, :class:`Nio.NioFile`

or an iterable sequence of the aforementioned types.

x (:obj:`float` or sequence): A single x-coordinate or a sequence

of x-coordinate values to be converted.

y (:obj:`float` or sequence): A single y-coordinate or a sequence

of y-coordinate values to be converted.

timeidx (:obj:`int` or :data:`wrf.ALL_TIMES`, optional): The

desired time index. This value can be a positive integer,

negative integer, or

:data:`wrf.ALL_TIMES` (an alias for None) to return

all times in the file or sequence. The default is 0.

squeeze (:obj:`bool`, optional): Set to False to prevent dimensions

with a size of 1 from being automatically removed from the shape

of the output. Default is True.

meta (:obj:`bool`, optional): Set to False to disable metadata and

return :class:`numpy.ndarray` instead of

:class:`xarray.DataArray`. Default is True.

stagger (:obj:`str`): By default, the latitude is returned on the mass

grid, but a staggered grid can be chosen with the following

options:

- 'm': Use the mass grid (default).

- 'u': Use the same staggered grid as the u wind component,

which has a staggered west_east (x) dimension.

- 'v': Use the same staggered grid as the v wind component,

which has a staggered south_north (y) dimension.

Returns:

:class:`xarray.DataArray` or :class:`numpy.ndarray`: The

latitude and longitude values whose leftmost dimension is 2

(0=latitude, 1=longitude).

If xarray is enabled and the *meta* parameter is True, then the result

will be a :class:`xarray.DataArray` object. Otherwise, the result will

be a :class:`numpy.ndarray` object with no metadata.

"""

if is_mapping(wrfin):

return _llxy_mapping(wrfin, x, y, xy_to_ll,

timeidx, stagger, squeeze, meta)

_key = get_id(wrfin)

_wrfin = get_iterable(wrfin)

return _xy_to_ll(x, y, _wrfin, timeidx, stagger, "cat", True, None,

_key, **{})

@set_latlon_metadata(xy=False)

def xy_to_ll_proj(x, y, meta=True, squeeze=True, map_proj=None, truelat1=None,

truelat2=None, stand_lon=None, ref_lat=None, ref_lon=None,

pole_lat=None, pole_lon=None, known_x=None, known_y=None,

dx=None, dy=None, latinc=None, loninc=None):

"""Return the latitude and longitude for the specified x,y coordinates.

The *x* and *y* arguments can be a single value or a

sequence of values. This version of the xy_to_ll routine allows users

to manually specify map projection parameters.

The leftmost dimension of the returned array represents two different

quantities:

- return_val[0,...] will contain the latitude values.

- return_val[1,...] will contain the longitude values.

Args:

x (:obj:`float` or sequence): A single x-coordinate or a sequence

of x-coordinate values to be converted.

y (:obj:`float` or sequence): A single y-coordinate or a sequence

of y-coordinate values to be converted.

squeeze (:obj:`bool`, optional): Set to False to prevent dimensions

with a size of 1 from being automatically removed from the shape

of the output. Default is True.

meta (:obj:`bool`, optional): Set to False to disable metadata and

return :class:`numpy.ndarray` instead of

:class:`xarray.DataArray`. Default is True.

map_proj (:obj:`int`): Model projection [1=Lambert Conformal,

2=Polar Stereographic, 3=Mercator, 6=Lat-Lon]. Required.

truelat1 (:obj:`float`): Latitude of true scale 1. Required for

map_proj = 1, 2, 3 (defaults to 0 otherwise).

truelat2 (:obj:`float`): Latitude of true scale 2. Optional for

map_proj = 1 (defaults to 0 otherwise).

stand_lon (:obj:`float`): Standard longitude. Required for *map_proj* =

1, 2, 6 (defaults to 0 otherwise).

ref_lat (:obj:`float`): A reference latitude. Required.

ref_lon (:obj:`float`): A reference longitude. Required.

known_x (:obj:`float`): The known x-coordinate associated with

*ref_lon*. Required.

known_y (:obj:`float`): The known y-coordinate associated with

*ref_lat*. Required.

pole_lat (:obj:`float`): Pole latitude. Required for

*map_proj* = 6 (use 90 for no rotation).

pole_lon (:obj:`float`): Pole longitude. Required for

*map_proj* = 6 (use 0 for no rotation).

dx (:obj:`float`): The x spacing in meters at the true latitude.

Required for all map projections.

dy (:obj:`float`) - The y spacing in meters at the true latitude.

Required for *map_proj* = 6 (defaults to 0 otherwise).

latinc (:obj:`float`): Optional for *map_proj* = 6. Default is:

.. code-block:: python

latinc = (dy*360.0)/2.0/Constants.PI/Constants.WRF_EARTH_RADIUS

loninc (:obj:`float`): Optional for *map_proj* = 6. Default is:

.. code-block:: python

loninc = (dx*360.0)/2.0/Constants.PI/Constants.WRF_EARTH_RADIUS

Returns:

:class:`xarray.DataArray` or :class:`numpy.ndarray`: The

latitude and longitude values whose leftmost dimension is 2

(0=latitude, 1=longitude).

If xarray is enabled and the *meta* parameter is True, then the result

will be a :class:`xarray.DataArray` object. Otherwise, the result will

be a :class:`numpy.ndarray` object with no metadata.

"""

loc = locals()

_projparams = {name: loc[name] for name in ("map_proj", "truelat1",

"truelat2", "stand_lon",

"ref_lat", "ref_lon",

"pole_lat", "pole_lon",

"known_x", "known_y", "dx",

"dy", "latinc", "loninc")}

projparams = _set_defaults(_projparams)

return _xy_to_ll(x, y, None, 0, None, "cat", squeeze, None, None,

**projparams)