MATLAB: Interpolate matrix functrion. Concatate n-dim matrices

concatatespapispval

Hi, all. I have two 3D matrixes (arrays of matrix function values and derivatives). And I need to concatate it to pass function spapi.
function test()
  t = linspace(0, 1, 10);
  for i = 1:length(t)
      a(:,:,i) = A(t(i));
      da(:,:,i) = dA(t(i));
  end
    % I need to obtain the following array:
    % [a(:, :, 1) a(:, :, 2) ... a(:, :, 10) da(:, :, 1) da(:, :, 2) ... da(:, :, 10)]
    y = [a da] % doesn't work



    y = [a; da] % doesn't work
    y = [a, da] % doesn't work
    % after i'd like to interpolate
    sp = spapi(4, [t t], y);
    disp(sp.coefs);
    disp(spval(sp, 0.21) - A(0.21)); % doesn't work
end
function a = A(t)
    a = [exp(t), exp(2*t); exp(3*t), exp(4*t)];
end
function a = dA(t)
    a = [exp(t), 2*exp(2*t); 3*exp(3*t), 4*exp(4*t)];
end
Hence 2 questions:
  1. How to concatate two 3D matrixes by third index?
  2. How to obtain values of interpolated function? spval(sp, 0.21) doesn't work for matrixes.

Best Answer

cat(3,A,B)
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