ENH: Add ndim to ArrayProxy protocol

Author: effigies

nibabel/arrayproxy.py

@@ -232,6 +232,10 @@ def header(self):
     def shape(self):
         return self._shape
 
+    @property
+    def ndim(self):
+        return len(self.shape)
+
     @property
     def dtype(self):
         return self._dtype

nibabel/ecat.py

@@ -680,6 +680,10 @@ def __init__(self, subheader):
     def shape(self):
         return self._shape
 
+    @property
+    def ndim(self):
+        return len(self.shape)
+
     @property
     def is_proxy(self):
         return True

nibabel/minc1.py

@@ -252,6 +252,10 @@ def __init__(self, minc_file):
     def shape(self):
         return self._shape
 
+    @property
+    def ndim(self):
+        return len(self.shape)
+
     @property
     def is_proxy(self):
         return True

nibabel/parrec.py

@@ -622,6 +622,10 @@ def __init__(self, file_like, header, mmap=True, scaling='dv'):
     def shape(self):
         return self._shape
 
+    @property
+    def ndim(self):
+        return len(self.shape)
+
     @property
     def dtype(self):
         return self._dtype