code: 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);
    }
  }
docs: 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.