Add ConstantOperator

nifty5/__init__.py

@@ -19,6 +19,7 @@ from .field import Field
 from .multi_field import MultiField
 
 from .operators.operator import Operator
+from .operators.constant_operator import ConstantOperator
 from .operators.central_zero_padder import CentralZeroPadder
 from .operators.diagonal_operator import DiagonalOperator
 from .operators.distributors import DOFDistributor, PowerDistributor
@@ -73,7 +74,7 @@ from .minimization.kl_energy import KL_Energy
 from .sugar import *
 from .plot import Plot
 
-from .library.amplitude_model import AmplitudeModel, GaussShiftModel
+from .library.amplitude_model import AmplitudeModel
 from .library.inverse_gamma_model import InverseGammaModel
 from .library.los_response import LOSResponse
 

nifty5/library/amplitude_model.py

@@ -23,6 +23,7 @@ import numpy as np
 from ..compat import *
 from ..domains.power_space import PowerSpace
 from ..field import Field
+from ..operators.constant_operator import ConstantOperator
 from ..operators.operator import Operator
 from ..sugar import makeOp, sqrt
 
@@ -93,22 +94,6 @@ def CepstrumOperator(logk_space, ceps_a, ceps_k, zero_mode=True):
     return res
 
 
-class GaussShiftModel(Operator):
-    # FIXME Remove this operator as soon as operators support addition with
-    # constant fields
-    def __init__(self, mean, std):
-        dom = mean.domain
-        dom1 = std.domain
-        if not dom == dom1:
-            raise TypeError('mean and std need to have the same domain.')
-        self._domain = self._target = dom
-        self._mean, self._std = mean, std
-
-    def apply(self, x):
-        self._check_input(x)
-        return self._std*x + self._mean
-
-
 def SlopeModel(logk_space, sm, sv, im, iv):
     '''
     Parameters
@@ -126,8 +111,7 @@ def SlopeModel(logk_space, sm, sv, im, iv):
     slope = SlopeOperator(logk_space)
     phi_mean = Field.from_global_data(slope.domain, phi_mean)
     phi_sig = Field.from_global_data(slope.domain, phi_sig)
-    gaussshift = GaussShiftModel(phi_mean, phi_sig)
-    return slope(gaussshift)
+    return slope*ConstantOperator(phi_sig) + ConstantOperator(phi_mean)
 
 
 def AmplitudeModel(s_space,

nifty5/operators/constant_operator.py

+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# 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) 2013-2018 Max-Planck-Society
+#
+# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
+# and financially supported by the Studienstiftung des deutschen Volkes.
+
+from __future__ import absolute_import, division, print_function
+
+from ..compat import *
+from ..multi_domain import MultiDomain
+from .operator import Operator
+
+
+class ConstantOperator(Operator):
+    def __init__(self, field):
+        self._field = field
+        self._domain = MultiDomain.make({})
+        self._target = field.domain
+
+    def apply(self, x):
+        self._check_input(x)
+        return self._field