add test

test/test_operators/test_convolution_operators.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) 2013-2019 Max-Planck-Society
+#
+# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik.
+
+from numpy.testing import assert_allclose, assert_equal
+
+import nifty5 as ift
+import numpy as np
+
+
+def gauss(x, sigma):
+    normalization = np.sqrt(2. * np.pi) * sigma
+    return np.exp(-0.5 * x * x / sigma**2) / normalization
+
+
+def test_rgspace():
+    N = 128
+    sigma = N/10**4
+    dom = ift.RGSpace(N)
+    sig = ift.exp(ift.from_random('normal', dom))
+    fco_op = ift.FuncConvolutionOperator(dom, lambda x: gauss(x, sigma))
+    sm_op = ift.HarmonicSmoothingOperator(dom, sigma)
+    assert_allclose(fco_op(sig).to_global_data(),
+                    sm_op(sig).to_global_data(),
+                    rtol=1e-05)
+    assert_allclose(fco_op.adjoint_times(sig).to_global_data(),
+                    sm_op.adjoint_times(sig).to_global_data(),
+                    rtol=1e-05)