Merge branch 'fixup_Student' into 'NIFTy_6'

Fix a bug where studentt would only work if theta is a scalar

See merge request ift/nifty!455

nifty6/operators/energy_operators.py

@@ -286,7 +286,7 @@ class StudentTEnergy(EnergyOperator):
     ----------
     domain : `Domain` or `DomainTuple`
         Domain of the operator
-    theta : Scalar
+    theta : Scalar or Field
         Degree of freedom parameter for the student t distribution
     """
 
@@ -296,10 +296,10 @@ class StudentTEnergy(EnergyOperator):
 
     def apply(self, x):
         self._check_input(x)
-        res = ((self._theta+1)/2)*(x**2/self._theta).ptw("log1p").sum()
+        res = (((self._theta+1)/2)*(x**2/self._theta).ptw("log1p")).sum()
         if not x.want_metric:
             return res
-        met = ScalingOperator(self.domain, (self._theta+1) / (self._theta+3))
+        met = makeOp((self._theta+1) / (self._theta+3), self.domain)
         return res.add_metric(met)
 
 

nifty6/sugar.py

@@ -345,7 +345,7 @@ def makeOp(input, dom=None):
     if np.isscalar(input):
         if not isinstance(dom, (DomainTuple, MultiDomain)):
             raise TypeError("need proper `dom` argument")
-        return SalingOperator(dom, input)
+        return ScalingOperator(dom, input)
     if dom is not None:
         if not dom == input.domain:
             raise ValueError("domain mismatch")

test/test_energy_gradients.py

@@ -74,6 +74,9 @@ def test_studentt(field):
         return
     energy = ift.StudentTEnergy(domain=field.domain, theta=.5)
     ift.extra.check_jacobian_consistency(energy, field, tol=1e-6)
+    theta = ift.from_random('normal',field.domain).exp()
+    energy = ift.StudentTEnergy(domain=field.domain, theta=theta)
+    ift.extra.check_jacobian_consistency(energy, field, tol=1e-6)
 
 
 def test_hamiltonian_and_KL(field):