Merge pull request #833 from CCI-Tools/832_dzelge_loading_sea_ice_dat…

…a_failed

832 dzelge loading sea ice data failed

CHANGES.md

@@ -7,6 +7,8 @@
 
 ## Version 2.0.0.dev24
 
+* Fixed failing download of Sea-Ice CCI data  (ValueError: The truth value of an array with more than one element is ambiguous)
+  [#832](https://github.com/CCI-Tools/cate/issues/832)
 * A set of related data access issues that all occurred if data was downloaded from ODP using a spatial subset
   has hopefully been addressed in one go. Issues include:
   - Cannot download SST dataset - I/O error. [#823](https://github.com/CCI-Tools/cate/issues/823) 

cate/core/opimpl.py

@@ -145,11 +145,15 @@ def _normalize_lat_lon_2d(ds: xr.Dataset) -> xr.Dataset:
 
     equal_lat = np.allclose(lat_data_1, lat_data_2, equal_nan=True)
     equal_lon = np.allclose(lon_data_1, lon_data_2, equal_nan=True)
-    if not (equal_lat and equal_lon):
-        return ds
+
+    # Drop lat lon in any case. If note qual_lat and equal_lon subset_spatial_impl will subsequently
+    # fail with a ValidationError
 
     ds = ds.drop(['lon', 'lat'])
 
+    if not (equal_lat and equal_lon):
+        return ds
+
     ds = ds.rename({
         x_dim_name: 'lon',
         y_dim_name: 'lat',
@@ -805,6 +809,16 @@ def subset_spatial_impl(ds: xr.Dataset,
     :param monitor: optional progress monitor
     :return: Subset dataset
     """
+
+    # Validate whether lat and lon exists.
+
+    if not hasattr(ds, 'lon') or not hasattr(ds, 'lat'):
+        raise ValidationError('Cannot apply regional subset. No (valid) geocoding found.')
+
+    if hasattr(ds, 'lon') and len(ds.lon.shape) != 1 \
+            or hasattr(ds, 'lat') and len(ds.lat.shape) != 1:
+        raise ValidationError('Geocoding not recognised. Variables "lat" and/or "lon" have more than one dimension.')
+
     monitor.start('Subset', 10)
     # Validate input
     try:

test/ops/test_subset.py

@@ -6,8 +6,11 @@
 
 import numpy as np
 import xarray as xr
+import pandas as pd
 
 from cate.core.op import OP_REGISTRY
+from cate.core.opimpl import subset_spatial_impl
+from cate.core.types import ValidationError
 from cate.ops import subset
 from cate.util.misc import object_to_qualified_name
 
@@ -19,7 +22,44 @@ def assert_dataset_equal(expected, actual):
     assert expected.equals(actual), (expected, actual)
 
 
+def get_test_subset_non_valid_lat_lon_dataset():
+    temp = np.random.randn(2, 2, 3)
+    precip = np.random.rand(2, 2, 3)
+    lon = [[-40, 40], [-40, 40]]
+    lat = [[-50, 50], [-50, 50]]
+    return xr.Dataset({'temp': (['x', 'y', 'time'], temp),
+                       'precip': (['x', 'y', 'time'], precip)},
+                      coords={'lon': (['x', 'y'], lon),
+                              'lat': (['x', 'y'], lat),
+                              'time': pd.date_range('2014-09-06', periods=3)})
+
+
 class TestSubsetSpatial(TestCase):
+    def test_subset_non_valid_lat_lon(self):
+        """
+        Test whether lat and/or lon exist and if they exist whether they have dimension = 1
+        :return: void
+        """
+
+        # Test whether lat lon exist
+        dataset = xr.Dataset({
+            'first': (['xc', 'yc', 'time'], np.ones([180, 360, 6])),
+            'second': (['xc', 'yc', 'time'], np.ones([180, 360, 6])),
+            'xc': np.linspace(-89.5, 89.5, 180),
+            'yc': np.linspace(-179.5, 179.5, 360),
+        })
+
+        with self.assertRaises(ValidationError) as error:
+            subset_spatial_impl(dataset, (-40, 40, -50, 50))
+        self.assertIn('No (valid) geocoding found', str(error.exception))
+
+        # test whether lat lon has the wrong dimension (!=1)
+        dataset = get_test_subset_non_valid_lat_lon_dataset()
+
+        with self.assertRaises(ValidationError) as error:
+            subset_spatial_impl(dataset, (-40, 40, -50, 50))
+        self.assertIn('Geocoding not recognised', str(error.exception))
+
     def test_nominal(self):
         """
         Test general 'most expected' use case functionality.