Merge branch 'correlated_field_names' into 'NIFTy_5'

choose mutifield key

See merge request ift/nifty-dev!108

nifty5/library/correlated_fields.py

@@ -46,7 +46,7 @@ def CorrelatedField(s_space, amplitude_model):
 
 
 def MfCorrelatedField(s_space_spatial, s_space_energy, amplitude_model_spatial,
-                      amplitude_model_energy):
+                      amplitude_model_energy, name="xi"):
     '''
     Method for construction of correlated multi-frequency fields
     '''
@@ -71,4 +71,4 @@ def MfCorrelatedField(s_space_spatial, s_space_energy, amplitude_model_spatial,
     a_energy = dom_distr_energy(amplitude_model_energy)
     a = a_spatial*a_energy
     A = pd(a)
-    return ht(A*FieldAdapter(MultiDomain.make({"xi": h_space}), "xi"))
+    return ht(A*FieldAdapter(MultiDomain.make({name: h_space}), name))

nifty5/linearization.py

@@ -178,6 +178,14 @@ class Linearization(object):
         return Linearization(field, NullOperator(field.domain, field.domain),
                              want_metric=want_metric)
 
+    @staticmethod
+    def make_const_empty_input(field, want_metric=False):
+        from .operators.simple_linear_operators import NullOperator
+        from .multi_domain import MultiDomain
+        return Linearization(
+            field, NullOperator(MultiDomain.make({}), field.domain),
+            want_metric=want_metric)
+
     @staticmethod
     def make_partial_var(field, constants, want_metric=False):
         from .operators.scaling_operator import ScalingOperator