# This software is open source software available under the BSD-3 license.
#
# Copyright (c) 2022 Triad National Security, LLC. All rights reserved.
# Copyright (c) 2022 Lawrence Livermore National Security, LLC. All rights
# reserved.
# Copyright (c) 2022 UT-Battelle, LLC. All rights reserved.
#
# Additional copyright and license information can be found in the LICENSE file
# distributed with this code, or at
# https://raw.githubusercontent.com/MPAS-Dev/MPAS-Analysis/master/LICENSE
import pyproj
import cartopy
known_comparison_grids = ['latlon', 'antarctic', 'arctic', 'north_atlantic',
'north_pacific']
[docs]def get_pyproj_projection(comparison_grid_name):
"""
Get the projection from the comparison_grid_name.
Parameters
----------
comparison_grid_name : {'antarctic', 'arctic', 'north_atlantic',
'north_pacific'}
The name of the projection comparison grid to use for remapping
Returns
-------
projection : pyproj.Proj
The projection
Raises
------
ValueError
If comparison_grid_name does not describe a known comparison grid
"""
# Authors
# -------
# Xylar Asay-Davis
# Milena Veneziani
# Yohei Takano
if comparison_grid_name not in known_comparison_grids:
raise ValueError(
f'Unknown comparison grid type {comparison_grid_name}')
if comparison_grid_name == 'latlon':
raise ValueError('latlon is not a projection grid.')
elif comparison_grid_name == 'antarctic':
projection = pyproj.Proj(
'+proj=stere +lat_ts=-71.0 +lat_0=-90 +lon_0=0.0 +k_0=1.0 '
'+x_0=0.0 +y_0=0.0 +ellps=WGS84')
elif comparison_grid_name == 'arctic':
projection = pyproj.Proj(
'+proj=stere +lat_ts=75.0 +lat_0=90 +lon_0=0.0 +k_0=1.0 '
'+x_0=0.0 +y_0=0.0 +ellps=WGS84')
elif comparison_grid_name == 'north_atlantic':
projection = pyproj.Proj('+proj=lcc +lon_0=-45 +lat_0=45 +lat_1=39 '
'+lat_2=51 +x_0=0.0 +y_0=0.0 +ellps=WGS84')
elif comparison_grid_name == 'north_pacific':
projection = pyproj.Proj('+proj=lcc +lon_0=180 +lat_0=40 +lat_1=34 '
'+lat_2=46 +x_0=0.0 +y_0=0.0 +ellps=WGS84')
else:
raise ValueError(f'We missed one of the known comparison grids: '
f'{comparison_grid_name}')
return projection
[docs]def get_cartopy_projection(comparison_grid_name):
"""
Get the projection from the comparison_grid_name.
Parameters
----------
comparison_grid_name : {'antarctic', 'arctic', 'north_atlantic',
'north_pacific'}
The name of the projection comparison grid to use for remapping
Returns
-------
projection : cartopy.crs.Projection
The projection
Raises
------
ValueError
If comparison_grid_name does not describe a known comparison grid
"""
# Authors
# -------
# Xylar Asay-Davis
# Milena Veneziani
# Yohei Takano
if comparison_grid_name not in known_comparison_grids:
raise ValueError(
f'Unknown comparison grid type {comparison_grid_name}')
if comparison_grid_name == 'latlon':
raise ValueError('latlon is not a projection grid.')
elif comparison_grid_name == 'antarctic':
projection = cartopy.crs.Stereographic(
central_latitude=-90., central_longitude=0.0,
true_scale_latitude=-71.0)
elif comparison_grid_name == 'arctic':
projection = cartopy.crs.Stereographic(
central_latitude=90., central_longitude=0.0,
true_scale_latitude=75.0)
elif comparison_grid_name == 'north_atlantic':
projection = cartopy.crs.LambertConformal(
central_latitude=45., central_longitude=-45.,
standard_parallels=(39., 51.))
elif comparison_grid_name == 'north_pacific':
projection = cartopy.crs.LambertConformal(
central_latitude=40., central_longitude=180.,
standard_parallels=(34., 46.))
else:
raise ValueError(f'We missed one of the known comparison grids: '
f'{comparison_grid_name}')
return projection