Merge 0c3187d into ac9bee7

ccdproc/combiner.py

@@ -43,10 +43,13 @@ class Combiner(object):
 
     """
 
-    def __init__(self, ccd_list):
+    def __init__(self, ccd_list, dtype=None):
         if ccd_list is None:
             raise TypeError("ccd_list should be a list of CCDData objects")
 
+        if dtype is None:
+            dtype = np.float64
+
         default_shape = None
         default_unit = None
         for ccd in ccd_list:
@@ -75,7 +78,7 @@ def __init__(self, ccd_list):
         #set up the data array
         ydim, xdim = default_shape
         new_shape = (len(ccd_list), ydim, xdim)
-        self.data_arr = ma.masked_all(new_shape)
+        self.data_arr = ma.masked_all(new_shape, dtype=dtype)
 
         #populate self.data_arr
         for i, ccd in enumerate(ccd_list):

ccdproc/tests/test_combiner.py

@@ -61,6 +61,13 @@ def test_combiner_create(ccd_data):
     assert c.data_arr.mask.shape == (3, 100, 100)
 
 
+#test if dtype matches the value that is passed
+def test_combiner_dtype(ccd_data):
+    ccd_list = [ccd_data, ccd_data, ccd_data]
+    c = Combiner(ccd_list, dtype = np.float32)
+    assert c.data_arr.dtype == np.float32
+
+
 #test mask is created from ccd.data
 def test_combiner_mask(ccd_data):
     data = np.zeros((10, 10))