Constant

core.Constant.Constant(self, name, value)

Constant parameter that can be used by all neurons and synapses.

The class Constant derives from float, so any legal operation on floats (addition, multiplication) can be used.

If a Neuron/Synapse defines a parameter with the same name, the constant parameters will not be visible.

Example:

tau = ann.Constant('tau', 20)
factor = ann.Constant('factor', 0.1)
real_tau = ann.Constant('real_tau', tau*factor)

neuron = ann.Neuron(
    equations='''
        real_tau*dr/dt + r =1.0
    '''
)

The value of the constant can be changed anytime with the set() method. Assignments will have no effect (e.g. tau = 10.0 only creates a new float).

The value of constants defined as combination of other constants (real_tau) is not updated if the value of these constants changes (changing tau with tau.set(10.0) will not modify the value of real_tau).

Parameters

Name	Type	Description	Default
name		name of the constant (unique), which can be used in equations.	required
value		the value of the constant, which must be a float, or a combination of Constants.	required

Attributes

Name	Description
name	Name.
value	Value.

Methods

Name	Description
set	Changes the value of the constant.

set

core.Constant.Constant.set(value, network=None)

Changes the value of the constant.

Parameters

Name	Type	Description	Default
value	float	Value.	required
network		Network instance which should be updated. By default, all active networks are updated.	None