how do i change parameters for a timespan t when the total time span for ODE simulation is T?

i am solving a systm on ODEs and need to alter rate constants to realise a biological function.

t = [500 1500]

T = [0 3000]

Answer 1

[Umang Pandey]

Hi Hetavi,

From what I understand you want to solve a time-dependent ODE where you need to alter the rate constants based on the time.

You can refer to the following example for understanding how to solve a time-dependent ODE :

https://www.mathworks.com/help/matlab/ref/ode45.html#bu3l43b

As for implementing a time-based rate constant, you can incorporate that within the definition of the ODE itself in the following way:

function dydt = myODE(t, y, params)
        % Check if the current time is within the timespan to change parameters
    if t >= 500 && t <= 1500
        k = params.changedRate; % Use the changed rate constant
    else
        k = params.normalRate; % Use the normal rate constant
    end

    dydt = ...; % Replace with your actual ODE system
end

Best,

Umang