progress

nifty5/multi/multi_field.py

@@ -210,6 +210,23 @@ class MultiField(object):
                 return False
         return True
 
+    def extract(self, subset):
+        if isinstance(subset, MultiDomain):
+            return MultiField(subset,
+                              tuple(self[key] for key in subset.keys()))
+        else:
+            return MultiField.from_dict({key: self[key] for key in subset})
+
+    @staticmethod
+    def combine(fields):
+        res = {}
+        for f in fields:
+            for key in f.keys():
+                if key in res:
+                    res[key] = res[key]+f[key]
+                else:
+                    res[key] = f[key]
+        return MultiField.from_dict(res)
 
 for op in ["__add__", "__radd__",
            "__sub__", "__rsub__",

nifty5/operator.py

@@ -10,8 +10,6 @@ from .utilities import NiftyMetaBase
 #from ..multi.multi_domain import MultiDomain
 from .field import Field
 from .multi.multi_field import MultiField
-from .operators.scaling_operator import ScalingOperator
-from .operators.diagonal_operator import DiagonalOperator
 
 
 class Linearization(object):
@@ -54,6 +52,7 @@ class Linearization(object):
         return (-self).__add__(other)
 
     def __mul__(self, other):
+        from .operators.diagonal_operator import DiagonalOperator
         if isinstance(other, Linearization):
             d1 = DiagonalOperator(self._val)
             d2 = DiagonalOperator(other._val)
@@ -77,9 +76,11 @@ class Linearization(object):
 
     @staticmethod
     def make_var(field):
+        from .operators.scaling_operator import ScalingOperator
         return Linearization(field, ScalingOperator(1., field.domain))
     @staticmethod
     def make_const(field):
+        from .operators.scaling_operator import ScalingOperator
         return Linearization(field, ScalingOperator(0., {}))
 
 class Operator(NiftyMetaBase()):

nifty5/operators/linear_operator.py

@@ -23,10 +23,10 @@ import abc
 import numpy as np
 
 from ..compat import *
-from ..utilities import NiftyMetaBase
+from ..operator import Operator, Linearization
 
 
-class LinearOperator(NiftyMetaBase()):
+class LinearOperator(Operator):
     """NIFTY base class for linear operators.
 
     The base NIFTY operator class is an abstract class from which
@@ -205,6 +205,8 @@ class LinearOperator(NiftyMetaBase()):
         """Same as :meth:`times`"""
         from ..models.model import Model
         from ..models.linear_model import LinearModel
+        if isinstance(x, Linearization):
+            return Linearization(self(x._val), self*x._jac)
         if isinstance(x, Model):
             return LinearModel(x, self)
         return self.apply(x, self.TIMES)