Specify variable or constant parameter value
ConstantValue property indicates whether
the value of a parameter can change during a simulation. Enter either
is constant) or
false (value can change).
You can allow the value of the parameter to change during a
simulation by specifying a rule that changes the
of the parameter object.
ConstantValue is for parameter
objects; the property
for species objects.
As an example, consider feedback inhibition of an enzyme such as aspartate kinase by threonine. Aspartate kinase has three isozymes that are independently inhibited by the products of downstream reactions (threonine, homoserine, and lysine). Although threonine is made through a series of reactions in the synthesis pathway, for illustration, the reactions are simplified as follows:
To model inhibition of aspartate kinase by threonine, you could
use a rule like the
algebraic rule below to vary
the rate of the above reaction and simulate inhibition. In the rule,
the rate constant for the above reaction is denoted by
the quantity of threonine is
|Applies to||Object: parameter|
Create a model object.
modelObj = sbiomodel ('my_model');
Add a parameter object.
parameterObj = addparameter (modelObj, 'kf');
of the parameter object from default (
set (parameterObj, 'ConstantValue', false); get(parameterObj, 'ConstantValue')
ans = 0