FIX: Accept dtype parameter to ArrayProxy.__array__

Author: effigies

nibabel/arrayproxy.py

@@ -405,8 +405,11 @@ def get_scaled(self, dtype=None):
         """
         return self._get_scaled(dtype=dtype, slicer=())
 
-    def __array__(self):
-        return self._get_scaled(dtype=None, slicer=())
+    def __array__(self, dtype=None):
+        arr = self._get_scaled(dtype=dtype, slicer=())
+        if dtype is not None:
+            arr = arr.astype(dtype, copy=False)
+        return arr
 
     def __getitem__(self, slicer):
         return self._get_scaled(dtype=None, slicer=slicer)

nibabel/ecat.py

@@ -689,15 +689,16 @@ def ndim(self):
     def is_proxy(self):
         return True
 
-    def __array__(self):
+    def __array__(self, dtype=None):
         ''' Read of data from file
 
         This reads ALL FRAMES into one array, can be memory expensive.
 
         If you want to read only some slices, use the slicing syntax
         (``__getitem__``) below, or ``subheader.data_from_fileobj(frame)``
         '''
-        data = np.empty(self.shape)
+        # dtype=None is interpreted as float64
+        data = np.empty(self.shape, dtype=dtype)
         frame_mapping = get_frame_order(self._subheader._mlist)
         for i in sorted(frame_mapping):
             data[:, :, :, i] = self._subheader.data_from_fileobj(

nibabel/minc1.py

@@ -290,9 +290,12 @@ def get_scaled(self, dtype=None):
         """
         return self._get_scaled(dtype=dtype, slicer=())
 
-    def __array__(self):
+    def __array__(self, dtype=None):
         ''' Read of data from file '''
-        return self._get_scaled(dtype=None, slicer=())
+        arr = self._get_scaled(dtype=dtype, slicer=())
+        if dtype is not None:
+            arr = arr.astype(dtype, copy=False)
+        return arr
 
     def __getitem__(self, sliceobj):
         """ Read slice `sliceobj` of data from file """

nibabel/parrec.py

@@ -699,8 +699,11 @@ def get_scaled(self, dtype=None):
         """
         return self._get_scaled(dtype=dtype, slicer=())
 
-    def __array__(self):
-        return self._get_scaled(dtype=None, slicer=())
+    def __array__(self, dtype=None):
+        arr = self._get_scaled(dtype=dtype, slicer=())
+        if dtype is not None:
+            arr = arr.astype(dtype, copy=False)
+        return arr
 
     def __getitem__(self, slicer):
         return self._get_scaled(dtype=None, slicer=slicer)