DOC: Update ArrayProxy docstrings

Author: effigies

nibabel/arrayproxy.py

@@ -78,7 +78,7 @@ def __init__(self, file_like, spec, mmap=True):
             File-like object or filename. If file-like object, should implement
             at least ``read`` and ``seek``.
         spec : object or tuple
-            Tuple must have length 2-5, with the following fields:
+            Tuple must have length 2-5, with the following values.
                 - shape : tuple
                     tuple of ints describing shape of data
                 - storage_dtype : dtype specifier
@@ -90,7 +90,7 @@ def __init__(self, file_like, spec, mmap=True):
                 - slope : float
                     Scaling factor for resulting data (default: 1.0)
                 - inter : float
-                    Intercept for rescaled dadta (default: 0.0)
+                    Intercept for rescaled data (default: 0.0)
             OR
             Header object implementing ``get_data_shape``, ``get_data_dtype``,
             ``get_data_offset``, ``get_slope_inter``
@@ -188,6 +188,11 @@ def __getitem__(self, slicer):
         return apply_read_scaling(raw_data, self._slope, self._inter)
 
     def reshape(self, shape):
+        ''' Return an ArrayProxy with a new shape, without modifying data
+
+        ``array_proxy.reshape(shape)`` is equivalent to
+        ``np.reshape(array_proxy, shape)``
+        '''
         size = np.prod(self._shape)
         if np.prod(shape) != size:
             raise ValueError("cannot reshape array of size {:d} into shape "

nibabel/tests/test_arrayproxy.py

@@ -90,18 +90,22 @@ def test_tuplespec():
     arr = np.arange(24, dtype=dtype).reshape(shape)
     bio.seek(16)
     bio.write(arr.tostring(order='F'))
+    # Create equivalent header and tuple specs
     hdr = FunkyHeader(shape)
     tuple_spec = (hdr.get_data_shape(), hdr.get_data_dtype(),
                   hdr.get_data_offset(), 1., 0.)
     ap_header = ArrayProxy(bio, hdr)
     ap_tuple = ArrayProxy(bio, tuple_spec)
+    # Header and tuple specs produce identical behavior
     for prop in ('shape', 'dtype', 'offset', 'slope', 'inter', 'is_proxy'):
         assert_equal(getattr(ap_header, prop), getattr(ap_tuple, prop))
     for method, args in (('get_unscaled', ()), ('__array__', ()),
                          ('__getitem__', ((0, 2, 1), ))
                          ):
         assert_array_equal(getattr(ap_header, method)(*args),
                            getattr(ap_tuple, method)(*args))
+    # Tuple-defined ArrayProxies have no header to store
+    assert_true(ap_tuple.header is None)
 
 
 def write_raw_data(arr, hdr, fileobj):