def geogrid_simulator(fpath, do_maps=True, map_kwargs=None):
"""Emulates geogrid.exe, which is useful when defining new WRF domains.
Parameters
----------
fpath: str
path to a namelist.wps file
do_maps: bool
if you want the simulator to return you maps of the grids as well
map_kwargs: dict
kwargs to pass to salem.Map()
Returns
-------
(grids, maps) with:
- grids: a list of Grids corresponding to the domains
defined in the namelist
- maps: a list of maps corresponding to the grids (if do_maps==True)
"""
with open(fpath) as f:
lines = f.readlines()
pargs = dict()
for l in lines:
s = l.split('=')
if len(s) < 2:
continue
s0 = s[0].strip().upper()
s1 = list(filter(None, s[1].strip().replace('\n', '').split(',')))
if s0 == 'PARENT_ID':
parent_id = [int(s) for s in s1]
if s0 == 'PARENT_GRID_RATIO':
parent_ratio = [int(s) for s in s1]
if s0 == 'I_PARENT_START':
i_parent_start = [int(s) for s in s1]
if s0 == 'J_PARENT_START':
j_parent_start = [int(s) for s in s1]
if s0 == 'E_WE':
e_we = [int(s) for s in s1]
if s0 == 'E_SN':
e_sn = [int(s) for s in s1]
if s0 == 'DX':
dx = float(s1[0])
if s0 == 'DY':
dy = float(s1[0])
if s0 == 'MAP_PROJ':
map_proj = s1[0].replace("'", '').strip().upper()
if s0 == 'REF_LAT':
pargs['lat_0'] = float(s1[0])
if s0 == 'REF_LON':
pargs['ref_lon'] = float(s1[0])
if s0 == 'TRUELAT1':
pargs['lat_1'] = float(s1[0])
if s0 == 'TRUELAT2':
pargs['lat_2'] = float(s1[0])
if s0 == 'STAND_LON':
pargs['lon_0'] = float(s1[0])
# Sometimes files are not complete
pargs.setdefault('lon_0', pargs['ref_lon'])
# define projection
if map_proj == 'LAMBERT':
pwrf = '+proj=lcc +lat_1={lat_1} +lat_2={lat_2} ' \
'+lat_0={lat_0} +lon_0={lon_0} ' \
'+x_0=0 +y_0=0 +a=6370000 +b=6370000'
pwrf = pwrf.format(**pargs)
elif map_proj == 'MERCATOR':
pwrf = '+proj=merc +lat_ts={lat_1} +lon_0={lon_0} ' \
'+x_0=0 +y_0=0 +a=6370000 +b=6370000'
pwrf = pwrf.format(**pargs)
elif map_proj == 'POLAR':
pwrf = '+proj=stere +lat_ts={lat_1} +lat_0=90.0 +lon_0={lon_0} ' \
'+x_0=0 +y_0=0 +a=6370000 +b=6370000'
pwrf = pwrf.format(**pargs)
else:
raise NotImplementedError('WRF proj not implemented yet: '
'{}'.format(map_proj))
pwrf = gis.check_crs(pwrf)
# get easting and northings from dom center (probably unnecessary here)
e, n = pyproj.transform(wgs84, pwrf, pargs['ref_lon'], pargs['lat_0'])
# LL corner
nx, ny = e_we[0] - 1, e_sn[0] - 1
x0 = -(nx - 1) / 2. * dx + e # -2 because of staggered grid
y0 = -(ny - 1) / 2. * dy + n
# parent grid
grid = gis.Grid(nxny=(nx, ny), x0y0=(x0, y0), dxdy=(dx, dy), proj=pwrf)
# child grids
out = [grid]
for ips, jps, pid, ratio, we, sn in zip(i_parent_start, j_parent_start,
parent_id, parent_ratio, e_we,
e_sn):
if ips == 1:
continue
ips -= 1
jps -= 1
we -= 1
sn -= 1
nx = we / ratio
ny = sn / ratio
if nx != (we / ratio):
raise RuntimeError('e_we and ratios are incompatible: '
'(e_we - 1) / ratio must be integer!')
if ny != (sn / ratio):
raise RuntimeError('e_sn and ratios are incompatible: '
'(e_sn - 1) / ratio must be integer!')
prevgrid = out[pid - 1]
xx, yy = prevgrid.corner_grid.x_coord, prevgrid.corner_grid.y_coord
dx = prevgrid.dx / ratio
dy = prevgrid.dy / ratio
grid = gis.Grid(nxny=(we, sn),
x0y0=(xx[ips], yy[jps]),
dxdy=(dx, dy),
pixel_ref='corner',
proj=pwrf)
out.append(grid.center_grid)
maps = None
if do_maps:
from salem import Map
import shapely.geometry as shpg
if map_kwargs is None:
map_kwargs = {}
maps = []
for i, g in enumerate(out):
m = Map(g, **map_kwargs)
for j in range(i + 1, len(out)):
cg = out[j]
left, right, bottom, top = cg.extent
s = np.array([(left, bottom), (right, bottom), (right, top),
(left, top)])
l1 = shpg.LinearRing(s)
m.set_geometry(l1,
crs=cg.proj,
linewidth=(len(out) - j),
zorder=5)
maps.append(m)
return out, maps
def geogrid_simulator(fpath, do_maps=True):
"""Emulates geogrid.exe, which is useful when defining new WRF domains.
Parameters
----------
fpath: str
path to a namelist.wps file
do_maps: bool
if you want the simulator to return you maps of the grids as well
Returns
-------
(grids, maps) with:
- grids: a list of Grids corresponding to the domains
defined in the namelist
- maps: a list of maps corresponding to the grids (if do_maps==True)
"""
with open(fpath) as f:
lines = f.readlines()
pargs = dict()
for l in lines:
s = l.split('=')
if len(s) < 2:
continue
s0 = s[0].strip().upper()
s1 = list(filter(None, s[1].strip().replace('\n', '').split(',')))
if s0 == 'PARENT_ID':
parent_id = [int(s) for s in s1]
if s0 == 'PARENT_GRID_RATIO':
parent_ratio = [int(s) for s in s1]
if s0 == 'I_PARENT_START':
i_parent_start = [int(s) for s in s1]
if s0 == 'J_PARENT_START':
j_parent_start = [int(s) for s in s1]
if s0 == 'E_WE':
e_we = [int(s) for s in s1]
if s0 == 'E_SN':
e_sn = [int(s) for s in s1]
if s0 == 'DX':
dx = float(s1[0])
if s0 == 'DY':
dy = float(s1[0])
if s0 == 'MAP_PROJ':
map_proj = s1[0].replace("'", '').strip().upper()
if s0 == 'REF_LAT':
pargs['lat_0'] = float(s1[0])
if s0 == 'REF_LON':
pargs['lon_0'] = float(s1[0])
if s0 == 'TRUELAT1':
pargs['lat_1'] = float(s1[0])
if s0 == 'TRUELAT2':
pargs['lat_2'] = float(s1[0])
# define projection
if map_proj == 'LAMBERT':
pwrf = '+proj=lcc +lat_1={lat_1} +lat_2={lat_2} ' \
'+lat_0={lat_0} +lon_0={lon_0} ' \
'+x_0=0 +y_0=0 +a=6370000 +b=6370000'
pwrf = pwrf.format(**pargs)
elif map_proj == 'MERCATOR':
pwrf = '+proj=merc +lat_ts={lat_1} ' \
'+lon_0={lon_0} ' \
'+x_0=0 +y_0=0 +a=6370000 +b=6370000'
pwrf = pwrf.format(**pargs)
else:
raise NotImplementedError('WRF proj not implemented yet: '
'{}'.format(map_proj))
pwrf = gis.check_crs(pwrf)
# get easting and northings from dom center (probably unnecessary here)
e, n = pyproj.transform(wgs84, pwrf, pargs['lon_0'], pargs['lat_0'])
# LL corner
nx, ny = e_we[0]-1, e_sn[0]-1
x0 = -(nx-1) / 2. * dx + e # -2 because of staggered grid
y0 = -(ny-1) / 2. * dy + n
# parent grid
grid = gis.Grid(nxny=(nx, ny), ll_corner=(x0, y0), dxdy=(dx, dy),
proj=pwrf)
# child grids
out = [grid]
for ips, jps, pid, ratio, we, sn in zip(i_parent_start, j_parent_start,
parent_id, parent_ratio,
e_we, e_sn):
if ips == 1:
continue
ips -= 1
jps -= 1
we -= 1
sn -= 1
nx = we / ratio
ny = sn / ratio
if nx != (we / ratio):
raise RuntimeError('e_we and ratios are incompatible: '
'(e_we - 1) / ratio must be integer!')
if ny != (sn / ratio):
raise RuntimeError('e_sn and ratios are incompatible: '
'(e_sn - 1) / ratio must be integer!')
prevgrid = out[pid - 1]
xx, yy = prevgrid.corner_grid.x_coord, prevgrid.corner_grid.y_coord
dx = prevgrid.dx / ratio
dy = prevgrid.dy / ratio
grid = gis.Grid(nxny=(we, sn),
ll_corner=(xx[ips], yy[jps]),
dxdy=(dx, dy),
pixel_ref='corner',
proj=pwrf)
out.append(grid.center_grid)
maps = None
if do_maps:
from salem import Map
import shapely.geometry as shpg
maps = []
for i, g in enumerate(out):
m = Map(g)
for j in range(i+1, len(out)):
cg = out[j]
left, right, bottom, top = cg.extent
s = np.array([(left, bottom), (right, bottom),
(right, top), (left, top)])
l1 = shpg.LinearRing(s)
m.set_geometry(l1, crs=cg.proj, linewidth=(len(out)-j))
maps.append(m)
return out, maps
