# Source code for spynnaker8.models.connectors.distance_dependent_probability_connector

```
# Copyright (c) 2017-2019 The University of Manchester
#
# 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/>.
from pyNN.connectors import (
DistanceDependentProbabilityConnector as
PyNNDistanceDependentProbabilityConnector)
from spynnaker.pyNN.models.neural_projections.connectors import (
DistanceDependentProbabilityConnector as
CommonDistanceDependentProbabilityConnector)
[docs]class DistanceDependentProbabilityConnector(
CommonDistanceDependentProbabilityConnector,
PyNNDistanceDependentProbabilityConnector):
""" Make connections using a distribution which varies with distance.
"""
__slots__ = []
def __init__(
self, d_expression, allow_self_connections=True, safe=True,
verbose=False, n_connections=None, rng=None, callback=None):
"""
:param `string` d_expression: \
the right-hand side of a valid python expression for\
probability, involving 'd', e.g. "exp(-abs(d))", or "d<3",\
that can be parsed by eval(), that computes the distance\
dependent distribution
:param `bool` allow_self_connections: \
if the connector is used to connect a\
Population to itself, this flag determines whether a neuron is\
allowed to connect to itself, or only to other neurons in the\
Population.
:param `int` n_connections: \
The number of efferent synaptic connections per neuron.
:param safe: if True, check that weights and delays have valid\
values. If False, this check is skipped.
"""
# pylint: disable=too-many-arguments
CommonDistanceDependentProbabilityConnector.__init__(
self, d_expression=d_expression,
allow_self_connections=allow_self_connections,
safe=safe, verbose=verbose, n_connections=n_connections)
PyNNDistanceDependentProbabilityConnector.__init__(
self, d_expression=d_expression,
allow_self_connections=allow_self_connections, rng=rng, safe=safe,
callback=callback)
```