brainpy.dyn.synapses.DeltaSynapse
brainpy.dyn.synapses.DeltaSynapse#
- class brainpy.dyn.synapses.DeltaSynapse(pre, post, conn, conn_type='sparse', weights=1.0, delay_step=None, post_key='V', post_has_ref=False, name=None)[source]#
Voltage Jump Synapse Model, or alias of Delta Synapse Model.
Model Descriptions
\[I_{syn} (t) = \sum_{j\in C} w \delta(t-t_j-D)\]where \(w\) denotes the chemical synaptic strength, \(t_j\) the spiking moment of the presynaptic neuron \(j\), \(C\) the set of neurons connected to the post-synaptic neuron, and \(D\) the transmission delay of chemical synapses. For simplicity, the rise and decay phases of post-synaptic currents are omitted in this model.
Model Examples
>>> import brainpy as bp >>> import matplotlib.pyplot as plt >>> >>> neu1 = bp.dyn.LIF(1) >>> neu2 = bp.dyn.LIF(1) >>> syn1 = bp.dyn.DeltaSynapse(neu1, neu2, bp.connect.All2All(), weights=5.) >>> net = bp.dyn.Network(pre=neu1, syn=syn1, post=neu2) >>> >>> runner = bp.dyn.DSRunner(net, inputs=[('pre.input', 25.), ('post.input', 10.)], monitors=['pre.V', 'post.V', 'pre.spike']) >>> runner.run(150.) >>> >>> fig, gs = bp.visualize.get_figure(1, 1, 3, 8) >>> plt.plot(runner.mon.ts, runner.mon['pre.V'], label='pre-V') >>> plt.plot(runner.mon.ts, runner.mon['post.V'], label='post-V') >>> plt.xlim(40, 150) >>> plt.legend() >>> plt.show()
(Source code, png, hires.png, pdf)
- Parameters
pre (NeuGroup) – The pre-synaptic neuron group.
post (NeuGroup) – The post-synaptic neuron group.
conn (optional, ndarray, JaxArray, dict of (str, ndarray), TwoEndConnector) – The synaptic connections.
conn_type (str) – The connection type used for model speed optimization. It can be sparse and dense. The default is sparse.
delay_step (int, ndarray, JaxArray, Initializer, Callable) – The delay length. It should be the value of \(\mathrm{delay\_time / dt}\).
weights (float, ndarray, JaxArray, Initializer, Callable) – The synaptic strength. Default is 1.
post_key (str) – The key of the post variable. It should be a string. The key should be the attribute of the post-synaptic neuron group.
post_has_ref (bool) – Whether the post-synaptic group has refractory period.
- __init__(pre, post, conn, conn_type='sparse', weights=1.0, delay_step=None, post_key='V', post_has_ref=False, name=None)[source]#
Methods
__init__
(pre, post, conn[, conn_type, ...])check_post_attrs
(*attrs)Check whether post group satisfies the requirement.
check_pre_attrs
(*attrs)Check whether pre group satisfies the requirement.
get_delay_data
(name, delay_step, *indices)Get delay data according to the provided delay steps.
ints
([method])Collect all integrators in this node and the children nodes.
load_states
(filename[, verbose])Load the model states.
nodes
([method, level, include_self])Collect all children nodes.
register_delay
(name, delay_step, delay_target)Register delay variable.
register_implicit_nodes
(nodes)register_implicit_vars
(variables)reset
()Reset function which reset the whole variables in the model.
reset_delay
(name, delay_target)Reset the delay variable.
save_states
(filename[, variables])Save the model states.
train_vars
([method, level, include_self])The shortcut for retrieving all trainable variables.
unique_name
([name, type_])Get the unique name for this object.
update
(t, dt)The function to specify the updating rule.
update_delay
(name, delay_data)Update the delay according to the delay data.
vars
([method, level, include_self])Collect all variables in this node and the children nodes.
Attributes
global_delay_vars
name
steps