# encoding: utf-8
"""
Alternative, procedural API for creating, connecting and recording from individual neurons
:copyright: Copyright 2006-2016 by the PyNN team, see AUTHORS.
:license: CeCILL, see LICENSE for details.
"""
from .populations import IDMixin, BasePopulation, Assembly
def build_create(population_class):
def create(cellclass, cellparams=None, n=1):
"""
Create `n` cells all of the same type.
Returns a Population object.
"""
return population_class(n, cellclass, cellparams=cellparams)
return create
def build_connect(projection_class, connector_class, static_synapse_class):
def connect(pre, post, weight=0.0, delay=None, receptor_type=None,
p=1, rng=None):
"""
Connect a source of spikes to a synaptic target.
`source` and `target` can both be individual cells or populations/
assemblies of cells, in which case all possible connections are made
with probability `p`, using either the random number generator supplied,
or the default RNG otherwise. Weights should be in nA or µS.
"""
if isinstance(pre, IDMixin):
pre = pre.as_view()
if isinstance(post, IDMixin):
post = post.as_view()
connector = connector_class(p_connect=p, rng=rng)
synapse = static_synapse_class(weight=weight, delay=delay)
return projection_class(pre, post, connector, receptor_type=receptor_type,
synapse_type=synapse)
return connect
[docs]def set(cells, **parameters):
"""
Set one or more parameters for every cell in a population, view or assembly.
Values passed to set() may be:
(1) single values
(2) RandomDistribution objects
(3) mapping functions, where a mapping function accepts a single
argument (the cell index) and returns a single value.
Here, a "single value" may be either a single number or a list/array of
numbers (e.g. for spike times). Values should be expressed in the standard
PyNN units (i.e. millivolts, nanoamps, milliseconds, microsiemens,
nanofarads, event per second).
"""
if not isinstance(cells, (BasePopulation, Assembly)):
errmsg = "For individual cells, set values using the parameter name directly, " \
"e.g. population[0].tau_m = 20.0, or use 'set' on a population view, " \
"e.g. set(population[0:1], tau_m=20.0)"
raise AttributeError(errmsg)
cells.set(**parameters)
def build_record(simulator):
def record(variables, source, filename, sampling_interval=None, annotations=None):
"""
Record variables to a file. source can be an individual cell, a
Population, PopulationView or Assembly.
"""
# would actually like to be able to record to an array and choose later
# whether to write to a file.
if not isinstance(source, (BasePopulation, Assembly)):
source = source.parent
source.record(variables, to_file=filename, sampling_interval=sampling_interval)
if annotations:
source.annotate(**annotations)
simulator.state.write_on_end.append((source, variables, filename))
return record
[docs]def initialize(cells, **initial_values):
"""
Set initial values of state variables, e.g. the membrane potential.
Values passed to initialize() may be:
(1) single numeric values (all neurons set to the same value)
(2) RandomDistribution objects
(3) lists/arrays of numbers of the same size as the population
(4) mapping functions, where a mapping function accepts a single
argument (the cell index) and returns a single number.
Values should be expressed in the standard PyNN units (i.e. millivolts,
nanoamps, milliseconds, microsiemens, nanofarads, event per second).
Examples::
initialize(cells, v=-70.0)
initialize(cells, v=rand_distr, gsyn_exc=0.0)
initialize(cells, v=lambda i: -65 + i/10.0)
"""
assert isinstance(cells, (BasePopulation, Assembly)), type(cells)
cells.initialize(**initial_values)
