Independent Variable

class pybamm.IndependentVariable(name, domain=None, auxiliary_domains=None)

A node in the expression tree representing an independent variable.

Used for expressing functions depending on a spatial variable or time

Parameters:

• name (str) – name of the node
• domain (iterable of str) – list of domains that this variable is valid over
• *Extends –

to_equation()

Convert the node and its subtree into a SymPy equation.

class pybamm.Time

A node in the expression tree representing time.

Extends: Symbol

create_copy()

See pybamm.Symbol.new_copy().

to_equation()

Convert the node and its subtree into a SymPy equation.

class pybamm.SpatialVariable(name, domain=None, auxiliary_domains=None, coord_sys=None)

A node in the expression tree representing a spatial variable.

Parameters:

• name (str) – name of the node (e.g. “x”, “y”, “z”, “r”, “x_n”, “x_s”, “x_p”, “r_n”, “r_p”)
• domain (iterable of str) – list of domains that this variable is valid over (e.g. “cartesian”, “spherical polar”)
• *Extends –

create_copy()

See pybamm.Symbol.new_copy().

pybamm.t = the independent variable time

A node in the expression tree representing time.

Extends: Symbol