efficiency tweaks

nifty4/operators/chain_operator.py

@@ -99,6 +99,14 @@ class ChainOperator(LinearOperator):
     def target(self):
         return self._ops[0].target
 
+    @property
+    def inverse(self):
+        return self.make([op.inverse for op in reversed(self._ops)])
+
+    @property
+    def adjoint(self):
+        return self.make([op.adjoint for op in reversed(self._ops)])
+
     @property
     def capability(self):
         return self._capability

nifty4/operators/scaling_operator.py

@@ -81,8 +81,7 @@ class ScalingOperator(EndomorphicOperator):
     def capability(self):
         if self._factor == 0.:
             return self.TIMES | self.ADJOINT_TIMES
-        return (self.TIMES | self.ADJOINT_TIMES |
-                self.INVERSE_TIMES | self.ADJOINT_INVERSE_TIMES)
+        return self._all_ops
 
     def draw_sample(self):
         return Field.from_random(random_type="normal",

nifty4/operators/sum_operator.py

@@ -122,6 +122,10 @@ class SumOperator(LinearOperator):
     def target(self):
         return self._ops[0].target
 
+    @property
+    def adjoint(self):
+        return self.make([op.adjoint for op in self._ops], self._neg)
+
     @property
     def capability(self):
         return self._capability