8000 add optional custom grid for merging gridded data by pat-schmitt · Pull Request #1779 · OGGM/oggm · GitHub
[go: up one dir, main page]
More Web Proxy on the site http://driver.im/
Skip to content

add optional custom grid for merging gridded data #1779

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 3 commits into
base: master
Choose a base branch
from
Open

add optional custom grid for merging gridded data #1779

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
9ec32a3
add optional custom grid for merging gridded data
pat-schmitt May 19, 2025
dcaa223
fix bug when reprojecting relatively small grid to a larger one
pat-schmitt 8000 May 20, 2025
c3af34c
fix bug when merging 3D data
pat-schmitt May 20, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
32 changes: 31 additions & 1 deletion oggm/core/gis.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1976,6 +1976,8 @@ def reproject_gridded_data_variable_to_grid(gdir,
total_before = (np.nansum(data.values, axis=sum_axis) *
ds.salem.grid.dx ** 2)

total_before_is_zero = np.isclose(total_before, 0, atol=1e-6)

if smooth_radius != 0:
if smooth_radius is None:
smooth_radius = np.rint(cfg.PARAMS['smooth_window'] /
Expand All @@ -1992,12 +1994,40 @@ def reproject_gridded_data_variable_to_grid(gdir,

total_after = (np.nansum(r_data, axis=sum_axis) *
target_grid.dx ** 2)
total_after_is_zero = np.isclose(total_after, 0, atol=1e-6)

# if a relatively small grid is reprojected into a larger grid, it
# could happen that no data is assigned at all
no_data_after_but_before = np.logical_and(total_after_is_zero,
~total_before_is_zero)
if np.any(no_data_after_but_before):
# we just assign the maximum value to one grid point and use the
# factor for conserving the total value
def _assign_max_value(data_provided, data_target):
j_max, i_max = np.unravel_index(
np.nanargmax(data_provided.values), data_provided.shape)
oi_max, oj_max = target_grid.center_grid.transform(
i_max, j_max, crs=gdir.grid.center_grid, nearest=True)
data_target[oj_max, oi_max] = data_provided[j_max, i_max]
return data_target

if r_data.ndim == 3:
for i in range(r_data.shape[0]):
if no_data_after_but_before[i]:
r_data[i, :, :] = _assign_max_value(data[i, :, :],
r_data[i, :, :])
else:
r_data = _assign_max_value(data, r_data)

# and recalculate the total after again
total_after = (np.nansum(r_data, axis=sum_axis) *
target_grid.dx ** 2)

# only preserve total if there is some data before
with warnings.catch_warnings():
# Divide by zero is fine
warnings.filterwarnings("ignore", category=RuntimeWarning)
factor = np.where(np.isclose(total_before, 0, atol=1e-6),
factor = np.where(total_before_is_zero,
0., total_before / total_after)

if len(data.dims) == 3:
Expand Down
7 changes: 7 additions & 0 deletions oggm/sandbox/distribute_2d.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -490,6 +490,7 @@ def distribute_thickness_from_simulation(gdir,
def merge_simulated_thickness(gdirs,
output_folder=None,
output_filename=None,
output_grid=None,
simulation_filesuffix='',
years_to_merge=None,
keep_dem_file=False,
Expand All @@ -514,6 +515,9 @@ def merge_simulated_thickness(gdirs,
output_folder
output_filename : str
Default is gridded_simulation_merged{simulation_filesuffix}.
output_grid : salem.gis.Grid
You can provide a custom grid on which the distributed data should be
merged on.
simulation_filesuffix : str
the filesuffix of the gridded_simulation file
years_to_merge : list | xr.DataArray | None
Expand Down Expand Up @@ -559,6 +563,7 @@ def _calc_bedrock_topo(fp):
gdirs,
output_folder=output_folder,
output_filename=f"{output_filename}_topo_data",
output_grid=output_grid,
input_file='gridded_data',
input_filesuffix='',
included_variables=['glacier_ext',
Expand Down Expand Up @@ -607,6 +612,7 @@ def _calc_bedrock_topo(fp):
gdirs,
output_folder=output_folder,
output_filename=f"{output_filename}_{year}_{month:02d}",
output_grid=output_grid,
input_file='gridded_simulation',
input_filesuffix=simulation_filesuffix,
included_variables=[('simulated_thickness',
Expand All @@ -632,6 +638,7 @@ def _calc_bedrock_topo(fp):
gdirs,
output_folder=output_folder,
output_filename=output_filename,
output_grid=output_grid,
input_file=['gridded_data', 'gridded_simulation'],
input_filesuffix=['', simulation_filesuffix],
included_variables=[['glacier_ext',
Expand Down
22 changes: 22 additions & 0 deletions oggm/tests/test_workflow.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -407,6 +407,28 @@ def test_merge_gridded_data():
assert_allclose(df['inv_volume_km3'].sum(), inv_volume_gridded_merged,
rtol=1e-6)

# test providing a custom grid
default_grid = utils.combine_grids(gdirs)
custom_grid_dict = default_grid.to_dict()
custom_grid_dict['nxny'] = (custom_grid_dict['nxny'][0] - 2,
custom_grid_dict['nxny'][1] - 2)
custom_grid = salem.gis.Grid.from_dict(custom_grid_dict)

ds_merged_custom = workflow.merge_gridded_data(
gdirs,
output_grid=custom_grid,
included_variables='distributed_thickness',
reset=True)

assert ds_merged_custom.salem.grid.nx < ds_merged.salem.grid.nx
assert ds_merged_custom.salem.grid.ny < ds_merged.salem.grid.ny

# total volume should be the same with a custom grid
inv_volume_gridded_merged_custom = (ds_merged_custom.distributed_thickness.sum() *
ds_merged_custom.salem.grid.dx ** 2) * 1e-9
assert_allclose(inv_volume_gridded_merged_custom, inv_volume_gridded_merged,
rtol=1e-6)


@pytest.mark.slow
@pytest.mark.graphic
Expand Down
24 changes: 15 additions & 9 deletions oggm/workflow.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -848,6 +848,7 @@ def _recursive_merging(gdirs, gdir_main, glcdf=None, dem_source=None,
@global_task(log)
def merge_gridded_data(gdirs, output_folder=None,
output_filename='gridded_data_merged',
output_grid=None,
input_file='gridded_data',
input_filesuffix='',
included_variables='all',
Expand Down Expand Up @@ -884,6 +885,10 @@ def merge_gridded_data(gdirs, output_folder=None,
should be stored. Default is cfg.PATHS['working_dir']
output_filename : str
The name for the resulting file. Default is 'gridded_data_merged'.
output_grid : salem.gis.Grid
You can provide a custom grid on which the gridded data should be
merged on. If None, a combined grid of all gdirs will be constructed.
Default is None.
input_file : str or list
The file(s) which should be merged. If a list is provided the data of
all files is merged into the same dataset. Default is 'gridded_data'.
Expand Down Expand Up @@ -970,9 +975,10 @@ def merge_gridded_data(gdirs, output_folder=None,
# into a list of lists
included_variables = [included_variables]

# create a combined salem.Grid object, which serves as canvas/boundaries of
# the combined glacier region
combined_grid = utils.combine_grids(gdirs)
if output_grid is None:
# create a combined salem.Grid object, which serves as canvas/boundaries of
# the combined glacier region
output_grid = utils.combine_grids(gdirs)

if add_topography:
# ok, lets get a DEM and add it to the final file
Expand All @@ -982,11 +988,11 @@ def merge_gridded_data(gdirs, output_folder=None,
else:
dem_source = None
dem_gdir = gdirs[0]
gis.get_dem_for_grid(combined_grid, output_folder,
gis.get_dem_for_grid(output_grid, output_folder,
source=dem_source, gdir=dem_gdir)
# unwrapped is needed to execute process_dem without the entity_task
# overhead (this would need a valid gdir)
gis.process_dem.unwrapped(gdir=None, grid=combined_grid,
gis.process_dem.unwrapped(gdir=None, grid=output_grid,
fpath=output_folder,
output_filename=output_filename)
if not keep_dem_file:
Expand All @@ -999,7 +1005,7 @@ def merge_gridded_data(gdirs, output_folder=None,
if os.path.exists(fpath):
os.remove(fpath)

with gis.GriddedNcdfFile(grid=combined_grid, fpath=output_folder,
with gis.GriddedNcdfFile(grid=output_grid, fpath=output_folder,
basename=output_filename) as nc:

# adding the data of one file after another to the merged dataset
Expand Down Expand Up @@ -1036,9 +1042,9 @@ def merge_gridded_data(gdirs, output_folder=None,
dim_lengths = []
for dim in dims:
if dim == 'y':
dim_lengths.append(combined_grid.ny)
dim_lengths.append(output_grid.ny)
elif dim == 'x':
dim_lengths.append(combined_grid.nx)
dim_lengths.append(output_grid.nx)
else:
if slice_of_var is not None:
# only keep selected part of the variable
Expand Down Expand Up @@ -1088,7 +1094,7 @@ def merge_gridded_data(gdirs, output_folder=None,

kwargs_reproject = dict(
variable=var,
target_grid=combined_grid,
target_grid=output_grid,
filename=in_file,
filesuffix=in_filesuffix,
use_glacier_mask=use_glacier_mask,
Expand Down
0