Mule mask (#12)

Author: Scott Wales

src/coecms/grid.py

@@ -20,6 +20,9 @@
 import xarray
 import numpy
 import iris
+import mule
+import os
+
 
 """
 Different grid types
@@ -178,11 +181,17 @@ def to_scrip(self):
 class UMGrid(LonLatGrid):
     @classmethod
     def from_mask(cls, mask_path):
-        mask = iris.load_cube(mask_path, iris.AttributeConstraint(STASH='m01s00i030'))
-        mask.coord('latitude').var_name = 'lat'
-        mask.coord('longitude').var_name = 'lon'
+        umfile = mule.load_umfile(mask_path)
+        mask_field = None
+        for f in umfile.fields:
+            if f.lbuser4 == 30:
+                mask_field = f
+                break
+
+        mask = xarray.DataArray(mask_field.get_data(), dims=['lat', 'lon'], name=os.path.basename(mask_path))
+        mask.coords['lon'] = mask_field.bzx + (1+numpy.arange(mask.shape[1])) * mask_field.bdx
+        mask.coords['lat'] = mask_field.bzy + (1+numpy.arange(mask.shape[0])) * mask_field.bdy
 
-        mask = xarray.DataArray.from_iris(mask).load()
         mask = mask.where(mask == 0)
 
         mask.lon.attrs['standard_name'] = 'longitude'