function computeHOAMatrices(matrix) {
  // We start by computing the 2nd-order matrix from the 1st-order matrix.
  for (let i = 2; i <= matrix.length; i++) {
    computeBandRotation(matrix, i);
  }
}
Compute the HOA rotation matrix after setting the transform matrix.
@param {Array} matrix - N matrices of gainNodes, each with (2n+1) x (2n+1)
elements, where n=1,2,...,N.