Skip to content
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

Fix handling of area creation in the grib reader #484

Merged
merged 2 commits into from
Nov 2, 2018
Merged

Fix handling of area creation in the grib reader #484

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
b701cf4
Fix handling of area creation in the grib reader
djhoese Nov 1, 2018
c404a93
Fix grib tests
djhoese Nov 1, 2018
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
18 changes: 11 additions & 7 deletions satpy/readers/grib.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -184,13 +184,15 @@ def _area_def_from_msg(self, msg):

proj = Proj(**proj_params)
x, y = proj(lons, lats)
x[np.abs(x) >= 1e30] = np.nan
y[np.abs(y) >= 1e30] = np.nan
min_x = np.nanmin(x)
max_x = np.nanmax(x)
min_y = np.nanmin(y)
max_y = np.nanmax(y)
extents = (min_x, min_y, max_x, max_y)
if msg.valid_key('jScansPositively') and msg['jScansPositively'] == 1:
min_x, min_y = x[0], y[0]
max_x, max_y = x[3], y[3]
else:
min_x, min_y = x[2], y[2]
max_x, max_y = x[1], y[1]
half_x = abs((max_x - min_x) / (shape[1] - 1)) / 2.
half_y = abs((max_y - min_y) / (shape[0] - 1)) / 2.
extents = (min_x - half_x, min_y - half_y, max_x + half_x, max_y + half_y)

return geometry.AreaDefinition(
'on-the-fly grib area',
Expand Down Expand Up @@ -251,6 +253,8 @@ def get_dataset(self, dataset_id, ds_info):
ds_info = self.get_metadata(msg, ds_info)
fill = msg['missingValue']
data = msg.values.astype(np.float32)
if msg.valid_key('jScansPositively') and msg['jScansPositively'] == 1:
data = data[::-1]

if isinstance(data, np.ma.MaskedArray):
data = data.filled(np.nan)
Expand Down
6 changes: 6 additions & 0 deletions satpy/tests/reader_tests/test_grib.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -37,6 +37,9 @@ def latlons(self):
def __getitem__(self, item):
return self.attrs[item]

def valid_key(self, key):
return True


class FakeGRIB(object):
"""Fake GRIB file returned by pygrib.open."""
Expand Down Expand Up @@ -66,6 +69,7 @@ def __init__(self, messages=None, proj_params=None, latlons=None):
minimum=100.,
maximum=200.,
typeOfLevel='isobaricInhPa',
jScansPositively=0,
proj_params=proj_params,
latlons=latlons,
),
Expand All @@ -88,6 +92,7 @@ def __init__(self, messages=None, proj_params=None, latlons=None):
minimum=100.,
maximum=200.,
typeOfLevel='isobaricInhPa',
jScansPositively=0,
proj_params=proj_params,
latlons=latlons,
),
Expand All @@ -110,6 +115,7 @@ def __init__(self, messages=None, proj_params=None, latlons=None):
minimum=100.,
maximum=200.,
typeOfLevel='isobaricInhPa',
jScansPositively=0,
proj_params=proj_params,
latlons=latlons,
),
Expand Down