Removed the dtype cast on qr function.

theano/sandbox/linalg/ops.py

@@ -1045,8 +1045,6 @@ class QRFull(Op):
 
         q[0], r[0] = self._numop(x,
                                  self.mode)
-        q[0] = q[0].astype(x.dtype)
-        r[0] = r[0].astype(x.dtype)
 
     def __str__(self):
         return self._numop.__name__.capitalize()
@@ -1083,8 +1081,6 @@ class QRIncomplete(Op):
         q[0] = self._numop(x,
                            self.mode)
 
-        q[0] = q[0].astype(x.dtype)
-
     def __str__(self):
         return self._numop.__name__.capitalize()