fixing bug with snap_to_grid on cpc lat lon input

added test using cpc_global-daily data

Author: aupiff

dweather_client/tests/test_utils.py

@@ -13,4 +13,12 @@ def test_snap_to_grid_prism():
     prism_metadata = http_client.get_metadata(heads['prism_precip-daily'])
     lat, lon = utils.snap_to_grid(39.8398, -104.193, prism_metadata)
     assert lat == 39.833
-    assert lon == -104.208
+    assert lon == -104.208
+
+def test_snap_to_grid_cpc_global_daily():
+    # tests snap_to_grid with ideosyncratic cpc lat/lon format
+    heads = http_client.get_heads()
+    prism_metadata = http_client.get_metadata(heads['cpc_global-daily'])
+    lat, lon = utils.snap_to_grid(69.754, 330.759, prism_metadata)
+    assert lat == 69.750
+    assert lon == 330.750

dweather_client/utils.py

@@ -21,16 +21,16 @@ def snap_to_grid(lat, lon, metadata):
     category = metadata['climate category']
 
     if 'cpc' in metadata['source data url']:
-        start[0], start[1] = conventional_lat_lon_to_cpc(start[0], start[1])
-        end[0], end[1] = conventional_lat_lon_to_cpc(end[0], end[1])
+        min_lat, min_lon = conventional_lat_lon_to_cpc(min_lat, min_lon)
+
     # check that the lat lon is in the bounding box
 
     if category != 'rainfall':
         raise Exception('snap_to_grid() called on non rainfall dataset.')
 
     snap_lat = round(round((lat - min_lat)/resolution) * resolution + min_lat, 3)
     snap_lon = round(round((lon - min_lon)/resolution) * resolution + min_lon, 3)
-    return snap_lat, snap_lon        
+    return snap_lat, snap_lon
 
 def cpc_lat_lon_to_conventional(lat, lon):
     """