|
| 1 | +# -*- coding: utf-8 -*- |
| 2 | +# |
| 3 | +# test_ticket_716.py |
| 4 | +# |
| 5 | +# This file is part of NEST. |
| 6 | +# |
| 7 | +# Copyright (C) 2004 The NEST Initiative |
| 8 | +# |
| 9 | +# NEST is free software: you can redistribute it and/or modify |
| 10 | +# it under the terms of the GNU General Public License as published by |
| 11 | +# the Free Software Foundation, either version 2 of the License, or |
| 12 | +# (at your option) any later version. |
| 13 | +# |
| 14 | +# NEST is distributed in the hope that it will be useful, |
| 15 | +# but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | +# GNU General Public License for more details. |
| 18 | +# |
| 19 | +# You should have received a copy of the GNU General Public License |
| 20 | +# along with NEST. If not, see <http://www.gnu.org/licenses/>. |
| 21 | + |
| 22 | +import nest |
| 23 | +import pytest |
| 24 | + |
| 25 | + |
| 26 | +def test_stdp_dopamine_synapse_weight_constant_without_presynaptic_spikes(): |
| 27 | + """ |
| 28 | + Regression test for Ticket #716. |
| 29 | +
|
| 30 | + Ensure that the weight of an stdp_dopamine_synapse is constant in the absence of presynaptic spiking. |
| 31 | + """ |
| 32 | + nest.ResetKernel() |
| 33 | + vt = nest.Create("volume_transmitter") |
| 34 | + nest.SetDefaults("stdp_dopamine_synapse", {"volume_transmitter": vt[0]}) |
| 35 | + |
| 36 | + n_pre = nest.Create("parrot_neuron") # does not fire |
| 37 | + n_post = nest.Create("parrot_neuron") |
| 38 | + n_dopa = nest.Create("parrot_neuron") |
| 39 | + |
| 40 | + sg_post = nest.Create("spike_generator", params={"spike_times": [0.5, 1.1, 3.4]}) |
| 41 | + sg_dopa = nest.Create("spike_generator", params={"spike_times": [1.4, 2.3, 4.6]}) |
| 42 | + |
| 43 | + nest.Connect(n_pre, n_post, syn_spec="stdp_dopamine_synapse") |
| 44 | + nest.Connect(sg_dopa, n_dopa) |
| 45 | + nest.Connect(n_dopa, vt) |
| 46 | + nest.Connect(sg_post, n_post) |
| 47 | + |
| 48 | + # Get initial weight |
| 49 | + conns = nest.GetConnections(synapse_model="stdp_dopamine_synapse") |
| 50 | + w0 = conns.get("weight") |
| 51 | + nest.Simulate(10.0) |
| 52 | + w1 = conns.get("weight") |
| 53 | + |
| 54 | + assert abs(w0 - w1) <= 1e-13, f"Weight changed: w0={w0}, w1={w1}" |
0 commit comments