How do i do moving average in s-function level 2?

Hi i want to do moving average in s-function level 2, When using matlab script i wrote this formula where r=residual with size 1, samples is the time step.

window=10;
 if samples > window

    sumS = 0;
    for l = 1:window,

      if l==1,
        S = (1/window) * (Htime(samples,:)) ./ R.^(1/2);
      else

        S= (1/window) * sum( (Htime(samples-(l-1):samples,:)) ./ R.^(1/2) );

      end;

      sumS=sumS + S*S';
    end;

    CovTime=((1/window)*sum(r(:,samples-window+1:samples)./ R.^(1/2))).^(2);
    CovEnsemble=S*Pold*S' + (1/window); 
    CovDifference = CovTime - CovEnsemble;

    if CovDifference > 0
      Qparameter = CovDifference / sumS;
    else
      Qparameter = 0;
    end;

the problem is when i am using s-function level 2, where i want to get this residual ~ r(:,samples-window+1:samples) , where i only have 1 data only when running the simulation. how do i get the previous data (residual) in s-function and to use in concurrently?

How do i define/ do it in s-function level 2? Thank you.

Answer 1

[Kaustubha Govind]

It looks like you need to maintain a "state" on the block. Please look into Using DWork Vectors in Level-2 MATLAB S-Function.

[dab483]

Hi, i am a bit confuse, if in matlab script to run the program i can just put for example

for sample: 1:L (where L is simulation length) EKF algorithm window =10 if samples >window ...... end

so if i define L=200 , means that i have 200 samples but in s-function with the sampling time and everything, the length becomes larger. I can just put the sampling time=1 (which is big) but it wont work in my simulink model. any advice?