Add test

test/test_operators/test_ptw_pre.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) 2021 Max-Planck-Society
+#
+# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik.
+
+import pytest
+
+import nifty7 as ift
+
+from ..common import setup_function, teardown_function
+
+pmp = pytest.mark.parametrize
+
+
+@pmp('f', [
+    'log', 'exp', 'sqrt', 'sin', 'cos', 'tan', 'sinc', 'sinh', 'cosh', 'tanh',
+    'absolute', 'reciprocal', 'sigmoid', 'log10', 'log1p', 'expm1', 'softplus',
+    ('power', 2.), ('exponentiate', 1.1)
+])
+def test_ptw_pre(f):
+    if not isinstance(f, tuple):
+        f = (f,)
+    op = ift.FFTOperator(ift.RGSpace(10))
+    op0 = op @ ift.ScalingOperator(op.domain, 1.).ptw(*f)
+    op1 = op.ptw_pre(*f)
+    pos = ift.from_random(op0.domain)
+    if f[0] in ['log', 'sqrt', 'log10', 'log1p']:
+        pos = pos.exp()
+    ift.extra.assert_equal(op0(pos), op1(pos))