Merge pull request #282 from swelborn/type-conversion-sparse-array

avoid type conversion to float on h5 import

python/stempy/io/sparse_array.py

@@ -202,8 +202,10 @@ def from_hdf5(cls, filepath, **init_kwargs):
         scan_shape = scan_shape[::-1]
 
         if version >= 3:
+            # Convert to int to avoid integer division that results in 
+            # a float
+            frames_per_scan = len(data) // np.prod(scan_shape, dtype=int)
             # Need to reshape the data, as it was flattened before saving
-            frames_per_scan = len(data) // np.prod(scan_shape)
             data = data.reshape((np.prod(scan_shape), frames_per_scan))
 
         # We may need to convert the version of the data