Comment on "Computation of the Fast Walsh-Fourier Transform"

Abstract

The matrix form of the Walsh functions as defined in the above-mentioned short note [1] can be generated by the modulo-2 product of two generating matrices: the natural binary code, and the transpose of the bit-reversed form of the first. As a result, the coefficients of the Walsh transform occur in bit-reversed order. By simply reordering the Walsh functions themselves to correspond to generation by the product of two such code matrices, neither or both in bit-reversed form, the Walsh coefficients occur in their natural order.