def lookup_map_feature(feature_name):
"""Get a Cartopy map feature based on a name."""
import cartopy.feature as cfeature
from . import cartopy_utils
name = feature_name.upper()
try:
feat = getattr(cfeature, name)
scaler = cfeature.AdaptiveScaler('110m', (('50m', 50), ('10m', 15)))
except AttributeError:
feat = getattr(cartopy_utils, name)
scaler = cfeature.AdaptiveScaler('20m', (('5m', 5), ('500k', 1)))
return feat.with_scale(scaler)
def _layer_features(self):
"""Iterate over all map features and return as Cartopy objects.
Handle converting names of maps to auto-scaling map features.
"""
for item in self.layers:
if is_string_like(item):
item = item.upper()
try:
scaler = cfeature.AdaptiveScaler('110m', (('50m', 50),
('10m', 15)))
feat = getattr(cfeature, item).with_scale(scaler)
except AttributeError:
scaler = cfeature.AdaptiveScaler('20m',
(('5m', 5), ('500k', 1)))
feat = getattr(cartopy_utils, item).with_scale(scaler)
else:
feat = item
yield feat
def plot(self, variable=None, vmin=None, vmax=None,
filename=None, title=None, buffer=1, lscale='auto'):
"""Plot geographical coverage of reader."""
fig = plt.figure()
if self.global_coverage():
lonmin=-180
lonmax=180
latmin=-89
latmax=89
else:
corners = self.xy2lonlat([self.xmin, self.xmin, self.xmax, self.xmax],
[self.ymax, self.ymin, self.ymax, self.ymin])
lonmin = np.min(corners[0]) - buffer*2
lonmax = np.max(corners[0]) + buffer*2
latmin = np.min(corners[1]) - buffer
latmax = np.max(corners[1]) + buffer
# Initialise map
if not self.global_coverage():
# Stereographic projection centred on domain, if small domain
x0 = (self.xmin + self.xmax) / 2
y0 = (self.ymin + self.ymax) / 2
lon0, lat0 = self.xy2lonlat(x0, y0)
sp = ccrs.Stereographic(central_longitude=lon0, central_latitude=lat0)
latmax = np.maximum(latmax, lat0)
latmin = np.minimum(latmin, lat0)
else:
# Global map if reader domain is large
sp = ccrs.Mercator()
ax = fig.add_subplot(1, 1, 1, projection=sp)
if lscale == 'auto': # Custom lscale - this should be generalized to Basemodel also
s = cfeature.AdaptiveScaler('coarse',
(('low', 100), ('intermediate', 20), ('high', 5), ('full', 1)))
lscale = s.scale_from_extent([lonmin, lonmax, latmin, latmax])
# GSHHS coastlines
f = cfeature.GSHHSFeature(scale=lscale, levels=[1])
f._geometries_cache = {}
ax.add_geometries(
#f.intersecting_geometries([lonmin, lonmax, latmin, latmax]),
f.geometries(),
ccrs.PlateCarree(),
facecolor=cfeature.COLORS['land'],
edgecolor='black')
gl = ax.gridlines(ccrs.PlateCarree())
gl.top_labels = False
# Get boundary
if self.global_coverage():
lon = np.array([-180, 180, 180, -180, -180])
lat = np.array([-89, -89, 89, 89, -89])
else:
npoints = 10 # points per side
x = np.array([])
y = np.array([])
x = np.concatenate((x, np.linspace(self.xmin, self.xmax, npoints)))
y = np.concatenate((y, [self.ymin]*npoints))
x = np.concatenate((x, [self.xmax]*npoints))
y = np.concatenate((y, np.linspace(self.ymin, self.ymax, npoints)))
x = np.concatenate((x, np.linspace(self.xmax, self.xmin, npoints)))
y = np.concatenate((y, [self.ymax]*npoints))
x = np.concatenate((x, [self.xmin]*npoints))
y = np.concatenate((y, np.linspace(self.ymax, self.ymin, npoints)))
# from x/y vectors create a Patch to be added to map
lon, lat = self.xy2lonlat(x, y)
lat[lat>89] = 89.
lat[lat<-89] = -89.
p = sp.transform_points(ccrs.PlateCarree(), lon, lat)
xsp = p[:, 0]
ysp = p[:, 1]
if variable is None:
boundary = Polygon(list(zip(xsp, ysp)), alpha=0.5, ec='k', fc='b',
zorder=100)
ax.add_patch(boundary)
if self.global_coverage():
ax.set_global()
else:
buf = (xsp.max()-xsp.min())*.1 # Some whitespace around polygon
ax.set_extent([xsp.min()-buf, xsp.max()+buf, ysp.min()-buf, ysp.max()+buf], crs=sp)
if title is None:
plt.title(self.name)
else:
plt.title(title)
plt.xlabel('Time coverage: %s to %s' %
(self.start_time, self.end_time))
if variable is not None:
rx = np.array([self.xmin, self.xmax])
ry = np.array([self.ymin, self.ymax])
if variable in self.derived_variables:
data = self.get_variables(self.derived_variables[variable], self.start_time, rx, ry)
self.__calculate_derived_environment_variables__(data)
else:
data = self.get_variables(variable, self.start_time, rx, ry)
rx, ry = np.meshgrid(data['x'], data['y'])
rx = np.float32(rx)
ry = np.float32(ry)
rlon, rlat = self.xy2lonlat(rx, ry)
data[variable] = np.ma.masked_invalid(data[variable])
if data[variable].ndim > 2:
logger.warning('Ensemble data, plotting only first member')
data[variable] = data[variable][0,:,:]
if self.global_coverage():
mappable = ax.pcolormesh(rlon, rlat, data[variable], vmin=vmin, vmax=vmax,
transform=ccrs.PlateCarree(), shading='nearest')
else:
p = sp.transform_points(ccrs.PlateCarree(), rlon, rlat)
mapx = p[:,:,0]
mapy = p[:,:,1]
mappable = ax.pcolormesh(mapx, mapy, data[variable], vmin=vmin, vmax=vmax,
shading='nearest')
cbar = fig.colorbar(mappable, orientation='horizontal', pad=.05, aspect=30, shrink=.4)
cbar.set_label(variable)
try: # Activate figure zooming
mng = plt.get_current_fig_manager()
mng.toolbar.zoom()
except:
pass
if filename is not None:
plt.savefig(filename)
plt.close()
else:
plt.show()
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with cartopy. If not, see <https://www.gnu.org/licenses/>.
from __future__ import (absolute_import, division, print_function)
import cartopy.feature as cfeature
small_extent = (-6, -8, 56, 59)
medium_extent = (-20, 20, 20, 60)
large_extent = (-40, 40, 0, 80)
auto_scaler = cfeature.AdaptiveScaler('110m', (('50m', 50), ('10m', 15)))
auto_land = cfeature.NaturalEarthFeature('physical', 'land', auto_scaler)
class TestFeatures(object):
def test_change_scale(self):
# Check that features can easily be retrieved with a different
# scale.
new_lakes = cfeature.LAKES.with_scale('10m')
assert new_lakes.scale == '10m'
assert new_lakes.kwargs == cfeature.LAKES.kwargs
assert new_lakes.category == cfeature.LAKES.category
assert new_lakes.name == cfeature.LAKES.name
def test_scale_from_extent(self):