equations package

Module handling equations and “code strings”, expressions or statements, used for example for the reset and threshold definition of a neuron.

Exported members: Equations, Expression, Statements

`codestrings` module

Module defining CodeString, a class for a string of code together with information about its namespace. Only serves as a parent class, its subclasses Expression and Statements are the ones that are actually used.

Exported members: Expression, Statements

Classes

CodeString(code)

A class for representing "code strings", i.e. a single Python expression or a sequence of Python statements.

Expression([code, sympy_expression])

Class for representing an expression.

Statements(code)

Class for representing statements.

Functions

is_constant_over_dt(expression, variables, ...)

Check whether an expression can be considered as constant over a time step.

`equations` module

Differential equations for Brian models.

Exported members: Equations

Classes

EquationError

Exception type related to errors in an equation definition.

Equations(eqns, **kwds)

Container that stores equations from which models can be created.

SingleEquation(type, varname, dimensions[, ...])

Class for internal use, encapsulates a single equation or parameter.

Functions

check_identifier_basic(identifier)

Check an identifier (usually resulting from an equation string provided by the user) for conformity with the rules.

check_identifier_constants(identifier)

Make sure that identifier names do not clash with function names.

check_identifier_functions(identifier)

Make sure that identifier names do not clash with function names.

check_identifier_reserved(identifier)

Check that an identifier is not using a reserved special variable name.

check_identifier_units(identifier)

Make sure that identifier names do not clash with unit names.

check_subexpressions(group, equations, ...)

Checks the subexpressions in the equations and raises an error if a subexpression refers to stateful functions without being marked as "constant over dt".

dimensions_and_type_from_string(unit_string)

Returns the physical dimensions that results from evaluating a string like "siemens / metre ** 2", allowing for the special string "1" to signify dimensionless units, the string "boolean" for a boolean and "integer" for an integer variable.

extract_constant_subexpressions(eqs)

is_stateful(expression, variables)

Whether the given expression refers to stateful functions (and is therefore not guaranteed to give the same result if called repetively).

parse_string_equations(eqns)

Parse a string defining equations.