Port test_global_rng from SLI to Py

Author: heplesser

testsuite/pytests/sli2py_mpi/test_global_rng.py

@@ -0,0 +1,50 @@
+# -*- coding: utf-8 -*-
+#
+# test_global_rng.py
+#
+# This file is part of NEST.
+#
+# Copyright (C) 2004 The NEST Initiative
+#
+# NEST 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 2 of the License, or
+# (at your option) any later version.
+#
+# NEST 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 NEST.  If not, see <http://www.gnu.org/licenses/>.
+
+import pandas as pd
+import pytest
+from mpi_test_wrapper import MPITestAssertAllRanksEqual
+
+
+# Parametrization over the number of nodes here only to show hat it works
+@pytest.mark.skipif_incompatible_mpi
+@MPITestAssertAllRanksEqual([1, 2, 4], debug=False)
+def test_global_rng():
+    """
+    Confirm that NEST random parameter used from the Python level uses globally sync'ed RNG correctly.
+    All ranks must report identical random number sequences independent of the number of ranks.
+
+    The test compares connection data written to OTHER_LABEL.
+    """
+
+    import nest
+
+    nest.rng_seed = 12
+    p = nest.CreateParameter("uniform", {"min": 0, "max": 1})
+
+    # Uncomment one of the two for loops to provoke failure
+    # for _ in range(nest.num_processes):
+    #     p.GetValue()
+    # for _ in range(nest.Rank()):
+    #     p.GetValue()
+
+    vals = pd.DataFrame([p.GetValue() for _ in range(5)])
+    vals.to_csv(OTHER_LABEL.format(nest.num_processes, nest.Rank()), sep="\t")  # noqa: F821