Do not change dtype of data during resampling.

Fix #82

CHANGES.md

@@ -6,6 +6,7 @@
 * Add recursive calculation of Pearson correlation coefficent.
 * Change H-SAF reading interface to use pygeobase consistently.
 * H07 reader now returns more variables.
+* Resampling interface now respects dtype of input data.
 
 
 # v0.3.6, 2015-12-10

pytesmo/grid/resample.py

@@ -160,9 +160,9 @@ def resample_to_grid(input_data, src_lon, src_lat, target_lon, target_lat,
         # construct arrays in output grid form
         if fill_value is not None:
             output_array = np.zeros(
-                output_swath.shape, dtype=np.float64) + fill_value
+                output_swath.shape, dtype=data.dtype) + fill_value
         else:
-            output_array = np.zeros(output_swath.shape, dtype=np.float64)
+            output_array = np.zeros(output_swath.shape, dtype=data.dtype)
             output_array = np.ma.array(output_array, mask=mask)
 
         neigh_slice = slice(None, None, None)

tests/test_grid/test_resample.py

@@ -70,6 +70,33 @@ def test_resample_to_zero_dot_one_deg(self):
             assert resampled_data[key].shape == lons_grid.shape
 
 
+def test_resample_dtypes():
+    """
+    Test if dtypes stay the same when resampling.
+    """
+
+    data = {'testint8': np.array([5, 5], dtype=np.int8),
+            'testfloat16': np.array([5, 5], dtype=np.float16)}
+
+    fill_values = {'testint8': 0,
+                   'testfloat16': 999.}
+    lons = np.array([0, 0.1])
+    lats = np.array([0, 0.1])
+    # lets resample to a 0.1 degree grid
+    # define the grid points in latitude and longitude
+    lats_dim = np.arange(-1, 1, 0.1)
+    lons_dim = np.arange(-1, 1, 0.1)
+    # make 2d grid out the 1D grid spacing
+    lons_grid, lats_grid = np.meshgrid(lons_dim, lats_dim)
+
+    resampled_data = resample.resample_to_grid(data, lons, lats,
+                                               lons_grid, lats_grid,
+                                               fill_values=fill_values)
+
+    for key in data:
+        assert resampled_data[key].shape == lons_grid.shape
+        assert resampled_data[key].dtype == data[key].dtype
+
 if __name__ == "__main__":
     # import sys;sys.argv = ['', 'Test.testName']
     unittest.main()