Performance tweak

nifty5/operators/model_gradient_operator.py

@@ -75,9 +75,9 @@ class ModelGradientOperator(LinearOperator):
             for dd in self.domain:
                 if dd in grad_keys:
                     res[dd] = self._gradients[dd].adjoint_times(x)
-                else:
-                    res[dd] = full(self.domain[dd], 0.)
+                # else:
+                    # res[dd] = full(self.domain[dd], 0.)
             res = MultiField(res)
-            if not res.domain == self.domain:
-                raise TypeError
+            # if not res.domain == self.domain:
+            #     raise TypeError
         return res

nifty5/operators/selection_operator.py

@@ -41,9 +41,10 @@ class SelectionOperator(LinearOperator):
         return self.TIMES | self.ADJOINT_TIMES
 
     def apply(self, x, mode):
+        # FIXME Is the copying necessary?
         self._check_input(x, mode)
         if mode == self.TIMES:
             return x[self._key].copy()
         else:
             from ..multi import MultiField
-            return MultiField({self._key: x})
+            return MultiField({self._key: x.copy()})