Apply time-history load in the App designer

Hi guys,

I'm now struggling how to realize the time-history loading in the app designer.

My problem is simple that I have a time periods of rainfall as well as Intensity for each during. In the original main file I use "heaviside function" like this:

    i_q = -(1/3600)*[0.0365 0.0697 0.0996 0.0493 0.0153];                 %FOR STEP LOADING: vector of rainfall intensity steps [m/s]
    T_q = 2*3600*[0.1 0.24 0.45 0.78 1];           %FOR STEP LOADING: vector of time intervals of rainfall intensities (2 hrs)
    q = @(t) (i_q(1).*(heaviside(t)-heaviside(t-T_q(1)))+ i_q(2).*(heaviside(t-T_q(1))-heaviside(t-T_q(2))) + i_q(3).*(heaviside(t-T_q(2))-heaviside(t-T_q(3))) + i_q(4).*(heaviside(t-T_q(3))-heaviside(t-T_q(4)))...
               + i_q(5).*(heaviside(t-T_q(4))-heaviside(t-T_q(5))));

which means when t lies in the first time interal (0<=t<=2*3600*0.1), the intensity will be the first elenment of i_q and so on, the time-intensity plot likes below:

Now in the app desinger, I want to let the user define their own time-history rainfall intensity (the length of column can depend on themselves) and load from excel file.

Could you please help me to figure it out?

Thank you very much!