def test_raster():
fig, ax = plt.subplots()
gdir = init_hef()
gis.gridded_attributes(gdir)
graphics.plot_raster(gdir, var_name='aspect', cmap='twilight', ax=ax)
fig.tight_layout()
return fig
def distribute_thickness_interp(gdir,
add_slope=True,
smooth_radius=None,
varname_suffix=''):
"""Compute a thickness map by interpolating between centerlines and border.
IMPORTANT: this is NOT what has been used for ITMIX. We used
distribute_thickness_per_altitude for ITMIX and global ITMIX.
This is a rather cosmetic task, not relevant for OGGM but for ITMIX.
Parameters
----------
gdir : :py:class:`oggm.GlacierDirectory`
the glacier directory to process
add_slope : bool
whether a corrective slope factor should be used or not
smooth_radius : int
pixel size of the gaussian smoothing. Default is to use
cfg.PARAMS['smooth_window'] (i.e. a size in meters). Set to zero to
suppress smoothing.
varname_suffix : str
add a suffix to the variable written in the file (for experiments)
"""
# Variables
grids_file = gdir.get_filepath('gridded_data')
# See if we have the masks, else compute them
with utils.ncDataset(grids_file) as nc:
has_masks = 'glacier_ext_erosion' in nc.variables
if not has_masks:
from oggm.core.gis import gridded_attributes
gridded_attributes(gdir)
with utils.ncDataset(grids_file) as nc:
glacier_mask = nc.variables['glacier_mask'][:]
glacier_ext = nc.variables['glacier_ext_erosion'][:]
ice_divides = nc.variables['ice_divides'][:]
if add_slope:
slope_factor = nc.variables['slope_factor'][:]
else:
slope_factor = 1.
# Thickness to interpolate
thick = glacier_ext * np.NaN
thick[(glacier_ext - ice_divides) == 1] = 0.
# TODO: domain border too, for convenience for a start
thick[0, :] = 0.
thick[-1, :] = 0.
thick[:, 0] = 0.
thick[:, -1] = 0.
# Along the lines
cls = gdir.read_pickle('inversion_output')
fls = gdir.read_pickle('inversion_flowlines')
vs = []
for cl, fl in zip(cls, fls):
vs.extend(cl['volume'])
x, y = utils.tuple2int(fl.line.xy)
thick[y, x] = cl['thick']
init_vol = np.sum(vs)
# Interpolate
xx, yy = gdir.grid.ij_coordinates
pnan = np.nonzero(~np.isfinite(thick))
pok = np.nonzero(np.isfinite(thick))
points = np.array((np.ravel(yy[pok]), np.ravel(xx[pok]))).T
inter = np.array((np.ravel(yy[pnan]), np.ravel(xx[pnan]))).T
thick[pnan] = griddata(points, np.ravel(thick[pok]), inter, method='cubic')
utils.clip_min(thick, 0, out=thick)
# Slope
thick *= slope_factor
# Smooth
dx = gdir.grid.dx
if smooth_radius != 0:
if smooth_radius is None:
smooth_radius = np.rint(cfg.PARAMS['smooth_window'] / dx)
thick = gaussian_blur(thick, np.int(smooth_radius))
thick = np.where(glacier_mask, thick, 0.)
# Re-mask
thick[glacier_mask == 0] = np.NaN
assert np.all(np.isfinite(thick[glacier_mask == 1]))
# Conserve volume
tmp_vol = np.nansum(thick * dx**2)
thick *= init_vol / tmp_vol
# write
grids_file = gdir.get_filepath('gridded_data')
with utils.ncDataset(grids_file, 'a') as nc:
vn = 'distributed_thickness' + varname_suffix
if vn in nc.variables:
v = nc.variables[vn]
else:
v = nc.createVariable(vn, 'f4', (
'y',
'x',
), zlib=True)
v.units = '-'
v.long_name = 'Distributed ice thickness'
v[:] = thick
return thick
def distribute_thickness_per_altitude(gdir,
add_slope=True,
smooth_radius=None,
dis_from_border_exp=0.25,
varname_suffix=''):
"""Compute a thickness map by redistributing mass along altitudinal bands.
This is a rather cosmetic task, not relevant for OGGM but for ITMIX.
Parameters
----------
gdir : :py:class:`oggm.GlacierDirectory`
the glacier directory to process
add_slope : bool
whether a corrective slope factor should be used or not
smooth_radius : int
pixel size of the gaussian smoothing. Default is to use
cfg.PARAMS['smooth_window'] (i.e. a size in meters). Set to zero to
suppress smoothing.
dis_from_border_exp : float
the exponent of the distance from border mask
varname_suffix : str
add a suffix to the variable written in the file (for experiments)
"""
# Variables
grids_file = gdir.get_filepath('gridded_data')
# See if we have the masks, else compute them
with utils.ncDataset(grids_file) as nc:
has_masks = 'glacier_ext_erosion' in nc.variables
if not has_masks:
from oggm.core.gis import gridded_attributes
gridded_attributes(gdir)
with utils.ncDataset(grids_file) as nc:
topo_smoothed = nc.variables['topo_smoothed'][:]
glacier_mask = nc.variables['glacier_mask'][:]
dis_from_border = nc.variables['dis_from_border'][:]
if add_slope:
slope_factor = nc.variables['slope_factor'][:]
else:
slope_factor = 1.
# Along the lines
cls = gdir.read_pickle('inversion_output')
fls = gdir.read_pickle('inversion_flowlines')
hs, ts, vs, xs, ys = [], [], [], [], []
for cl, fl in zip(cls, fls):
hs = np.append(hs, fl.surface_h)
ts = np.append(ts, cl['thick'])
vs = np.append(vs, cl['volume'])
x, y = fl.line.xy
xs = np.append(xs, x)
ys = np.append(ys, y)
init_vol = np.sum(vs)
# Assign a first order thickness to the points
# very inefficient inverse distance stuff
thick = glacier_mask * np.NaN
for y in range(thick.shape[0]):
for x in range(thick.shape[1]):
phgt = topo_smoothed[y, x]
# take the ones in a 100m range
starth = 100.
while True:
starth += 10
pok = np.nonzero(np.abs(phgt - hs) <= starth)[0]
if len(pok) != 0:
break
sqr = np.sqrt((xs[pok] - x)**2 + (ys[pok] - y)**2)
pzero = np.where(sqr == 0)
if len(pzero[0]) == 0:
thick[y, x] = np.average(ts[pok], weights=1 / sqr)
elif len(pzero[0]) == 1:
thick[y, x] = ts[pzero]
else:
raise RuntimeError('We should not be there')
# Distance from border (normalized)
dis_from_border = dis_from_border**dis_from_border_exp
dis_from_border /= np.mean(dis_from_border[glacier_mask == 1])
thick *= dis_from_border
# Slope
thick *= slope_factor
# Smooth
dx = gdir.grid.dx
if smooth_radius != 0:
if smooth_radius is None:
smooth_radius = np.rint(cfg.PARAMS['smooth_window'] / dx)
thick = gaussian_blur(thick, np.int(smooth_radius))
thick = np.where(glacier_mask, thick, 0.)
# Re-mask
utils.clip_min(thick, 0, out=thick)
thick[glacier_mask == 0] = np.NaN
assert np.all(np.isfinite(thick[glacier_mask == 1]))
# Conserve volume
tmp_vol = np.nansum(thick * dx**2)
thick *= init_vol / tmp_vol
# write
with utils.ncDataset(grids_file, 'a') as nc:
vn = 'distributed_thickness' + varname_suffix
if vn in nc.variables:
v = nc.variables[vn]
else:
v = nc.createVariable(vn, 'f4', (
'y',
'x',
), zlib=True)
v.units = '-'
v.long_name = 'Distributed ice thickness'
v[:] = thick
return thick
