Algorithm 358: singular value decomposition of a complex matrix [F1, 4, 5]

procedure Ising (n, x, t, S); integer n, x, l; integer array S; comment Ising generates n-sequences ($1, "", S,) of zeros and ones where x = ~i~ S~ and t = ~,-~1 I S~+I -S~ I are given. The main idea is to interleave compositions of x and n --x objects and resort to a lexicographic generation of compositions. We call these sequences Ising configurations since we believe they first appeared in the study of the so-called Ising