Source code for brian2.equations.refractory

Module implementing Brian's refractory mechanism.

from brian2.units.allunits import second
from brian2.units.fundamentalunits import DIMENSIONLESS

from .equations import (

__all__ = ["add_refractoriness"]

[docs] def check_identifier_refractory(identifier): """ Check that the identifier is not using a name reserved for the refractory mechanism. The reserved names are `not_refractory`, `refractory`, `refractory_until`. Parameters ---------- identifier : str The identifier to check. Raises ------ ValueError If the identifier is a variable name used for the refractory mechanism. """ if identifier in ("not_refractory", "refractory", "refractory_until"): raise SyntaxError( f"The name '{identifier}' is used in the refractory mechanism " " and should not be used as a variable " "name." )
[docs] def add_refractoriness(eqs): """ Extends a given set of equations with the refractory mechanism. New parameters are added and differential equations with the "unless refractory" flag are changed so that their right-hand side is 0 when the neuron is refractory (by multiplication with the ``not_refractory`` variable). Parameters ---------- eqs : `Equations` The equations without refractory mechanism. Returns ------- new_eqs : `Equations` New equations, with added parameters and changed differential equations having the "unless refractory" flag. """ new_equations = [] # replace differential equations having the active flag for eq in eqs.values(): if eq.type == DIFFERENTIAL_EQUATION and "unless refractory" in eq.flags: # the only case where we have to change anything new_code = f"int(not_refractory)*({eq.expr.code})" new_equations.append( SingleEquation( DIFFERENTIAL_EQUATION, eq.varname, eq.dim, expr=Expression(new_code), flags=eq.flags, ) ) else: new_equations.append(eq) # add new parameters new_equations.append( SingleEquation(PARAMETER, "not_refractory", DIMENSIONLESS, var_type=BOOLEAN) ) new_equations.append(SingleEquation(PARAMETER, "lastspike", second.dim)) return Equations(new_equations)