crash in detrend function

[stephanschulz]

Thank you for also making this javascript version of your C++ code. It's awesome.

I ran your JS code successfully but am trying now to combine it with a handpose tracker in order to see if i can get a BPM from the palm of my hand.

I am using this opencv.js helper for my p5js project.
https://github.com/orgicus/p5.js-cv#installation

But the app crashes after running for a while at cv.split(a_signal, s); line.
Would you have any idea why that might be?
It's interesting that step variable in the console says "Exception: TypeError" when usually it is 2.

// Remove trend in a_signal
function detrend(a_signal, lambda) {
    let h = cv.Mat.zeros(a_signal.rows-2, a_signal.rows, cv.CV_32FC1);
    let i = cv.Mat.eye(a_signal.rows, a_signal.rows, cv.CV_32FC1);
    let t1 = cv.Mat.ones(a_signal.rows-2, 1, cv.CV_32FC1)
    let t2 = cv.matFromArray(a_signal.rows-2, 1, cv.CV_32FC1,
                             new Array(a_signal.rows-2).fill(-2));
    let t3 = new cv.Mat();
    t1.copyTo(h.diag(0)); t2.copyTo(h.diag(1)); t1.copyTo(h.diag(2));
    cv.gemm(h, h, lambda*lambda, t3, 0, h, cv.GEMM_1_T);
    cv.add(i, h, h, t3, -1);
    cv.invert(h, h, cv.DECOMP_LU);
    cv.subtract(i, h, h, t3, -1);
    let s = new cv.MatVector();
    console.log({a_signal});
    cv.split(a_signal, s); //crash here
     console.log({s});
    cv.gemm(h, s.get(0), 1, t3, 0, s.get(0), 0);
    cv.gemm(h, s.get(1), 1, t3, 0, s.get(1), 0);
    cv.gemm(h, s.get(2), 1, t3, 0, s.get(2), 0);
    cv.merge(s, a_signal);
    h.delete(); i.delete();
    t1.delete(); t2.delete(); t3.delete();
    s.delete();
}

[AbhishekAnand-1]

[stephanschulz]
how can I run that program? on my computer.