Add Integration operator

nifty6/__init__.py

@@ -25,7 +25,7 @@ from .operators.adder import Adder
 from .operators.diagonal_operator import DiagonalOperator
 from .operators.distributors import DOFDistributor, PowerDistributor
 from .operators.domain_tuple_field_inserter import DomainTupleFieldInserter
-from .operators.contraction_operator import ContractionOperator
+from .operators.contraction_operator import ContractionOperator, IntegrationOperator
 from .operators.linear_interpolation import LinearInterpolator
 from .operators.endomorphic_operator import EndomorphicOperator
 from .operators.harmonic_operators import (

nifty6/linearization.py

@@ -11,7 +11,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
-# Copyright(C) 2013-2019 Max-Planck-Society
+# Copyright(C) 2013-2020 Max-Planck-Society
 #
 # NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik.
 
@@ -270,10 +270,8 @@ class Linearization(Operator):
         Linearization
             the (partial) integral
         """
-        from .operators.contraction_operator import ContractionOperator
-        return self.new(
-            self._val.integrate(spaces),
-            ContractionOperator(self._jac.target, spaces, 1)(self._jac))
+        from .operators.contraction_operator import IntegrationOperator
+        return IntegrationOperator(self._target, spaces)(self)
 
     def ptw(self, op, *args, **kwargs):
         t1, t2 = self._val.ptw_with_deriv(op, *args, **kwargs)

nifty6/operator_spectrum.py

@@ -11,7 +11,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
-# Copyright(C) 2013-2019 Max-Planck-Society
+# Copyright(C) 2013-2020 Max-Planck-Society
 
 import numpy as np
 import scipy.sparse.linalg as ssl

nifty6/operators/contraction_operator.py

@@ -11,7 +11,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
-# Copyright(C) 2013-2019 Max-Planck-Society
+# Copyright(C) 2013-2020 Max-Planck-Society
 #
 # NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik.
 
@@ -69,3 +69,9 @@ class ContractionOperator(LinearOperator):
                 x = x.weight(self._weight, spaces=self._spaces)
             res = x.sum(self._spaces)
             return res if isinstance(res, Field) else Field.scalar(res)
+
+
+def IntegrationOperator(domain, spaces):
+    domain = DomainTuple.make(domain)
+    swgt = domain.scalar_weight(spaces)
+    return ContractionOperator(domain, spaces, swgt)

nifty6/operators/operator.py

@@ -128,6 +128,10 @@ class Operator(metaclass=NiftyMeta):
         from .contraction_operator import ContractionOperator
         return ContractionOperator(self.target, spaces)(self)
 
+    def intergate(self, spaces=None):
+        from .contraction_operator import IntegrationOperator
+        return IntegrationOperator(self.target, spaces)(self)
+
     def vdot(self, other):
         from ..sugar import makeOp
         if not isinstance(other, Operator):