Don't recast nomask int arrays

SciTools · Mar 14, 2017 · f6f14fd · f6f14fd
1 parent 7b158c2
commit f6f14fd
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Showing 2 changed files with 9 additions and 7 deletions.
diff --git a/lib/iris/_lazy_data.py b/lib/iris/_lazy_data.py
@@ -81,7 +81,7 @@ def array_masked_to_nans(array):
 
     Args:
 
-    * masked_array:
+    * array:
         A NumPy `ndarray` or masked array.
 
     Returns:
@@ -100,10 +100,11 @@ def array_masked_to_nans(array):
     if not ma.isMaskedArray(array):
         result = array
     else:
-        if array.dtype.kind == 'i':
-            array = array.astype(np.dtype('f8'))
-        mask = array.mask
-        array[mask] = np.nan
+        if ma.is_masked(array):
+            if array.dtype.kind == 'i':
+                array = array.astype(np.dtype('f8'))
+            mask = array.mask
+            array[mask] = np.nan
         result = array.data
     return result
 

diff --git a/lib/iris/tests/unit/lazy_data/test_array_masked_to_nans.py b/lib/iris/tests/unit/lazy_data/test_array_masked_to_nans.py
@@ -89,12 +89,13 @@ def test_unmasked__integers(self):
         self.assertIs(result, unmasked_array)
 
     def test_no_mask__integers(self):
-        masked_array = ma.masked_array([1, 2], mask=ma.nomask)
+        datatype = np.dtype('i4')
+        masked_array = ma.masked_array([1, 2], dtype=datatype, mask=ma.nomask)
 
         result = array_masked_to_nans(masked_array)
 
         self._common_checks(result)
-        self.assertEqual(result.dtype, np.dtype('f8'))
+        self.assertEqual(result.dtype, datatype)
 
 
 if __name__ == '__main__':