adjust to changes on NIFTy_5 branch

nifty5/linearization.py

@@ -93,12 +93,16 @@ class Linearization(object):
     def __rsub__(self, other):
         return (-self).__add__(other)
 
+    def __truediv__(self, other):
+        if isinstance(other, Linearization):
+            return self.__mul__(other.inverse())
+        return self.__mul__(1./other)
+
     def __rtruediv__(self, other):
-        return (self.inverse()).__mul__(other)
+        return self.inverse().__mul__(other)
 
     def inverse(self):
-        return Linearization(1./self._val,
-                makeOp(-1./(self._val**2))(self._jac))
+        return self.new(1./self._val, makeOp(-1./(self._val**2))(self._jac))
 
     def __mul__(self, other):
         from .sugar import makeOp

nifty5/operators/energy_operators.py

@@ -112,6 +112,7 @@ class PoissonianEnergy(EnergyOperator):
         metric = SandwichOperator.make(x.jac, makeOp(1./x.val))
         return res.add_metric(metric)
 
+
 class InverseGammaLikelihood(EnergyOperator):
     def __init__(self, op, d):
         self._op, self._d = op, d
@@ -122,11 +123,12 @@ class InverseGammaLikelihood(EnergyOperator):
         res = 0.5*(x.log().sum() + (0.5/x).vdot(self._d))
         if not isinstance(x, Linearization):
             return Field.scalar(res)
+        if not x.want_metric:
+            return res
         metric = SandwichOperator.make(x.jac, makeOp(0.5/(x.val**2)))
         return res.add_metric(metric)
 
 
-
 class BernoulliEnergy(EnergyOperator):
     def __init__(self, p, d):
         self._p = p