Issue No. 05 - May (1971 vol. 20)
S.R. Webb , Mathematical Sciences Dep. Inform. Sys. Div. McDonnell Douglas Astronautics Co.
An algorithm for a fast matrix transform of order twelve was given by Pratt . The resulting transform matrix consists of plus and minus ones, is in order of sequency, but is not orthogonal, and hence is not a Hadamard matrix. This note proves it is impossible to construct a Hadamard matrix of order twelve with this increasing sequency property and gives a corrected algorithm of order twelve.
Algorithm, data reduction, Hadamard matrix, Hadamard transform, matrix factorization.
S.R. Webb, J.D. Kennedy, "Some Comments on the Fast Hadamard Transform of Order Twelve", IEEE Transactions on Computers, vol. 20, no. , pp. 588-590, May 1971, doi:10.1109/T-C.1971.223305