/* Name: mult.c Created: Sun Mar 30 17:29:45 1986 Last modified: Sun Mar 30 21:34:34 1986 Purpose: Multiply the two complex vectors, point by point. Details: Vectors are in the form: real, imaginary (each a floating number). A vector can be of any size. Computes v3 = v1 * v2. v3 should as big as the biggest of v1 and v2. Author: Bill Hoff,2-114C,8645,3563478 (hoff) at uicsl */ int mult (double *v1[2], int size1, double *v2[2], int size2, double *v3[2], int size3) { register int i, n; n = (size1 < size2 ? size1 : size2); /* get the smaller size */ for (i=0; i < n; i++) { *(v3[0]+i) = *(v1[0]+i) * *(v2[0]+i) - *(v1[1]+i) * *(v2[1]+i); *(v3[1]+i) = *(v1[0]+i) * *(v2[1]+i) + *(v2[0]+i) * *(v1[1]+i); } /* if unequal size, zero out remaining elements of larger vector */ if (size1 != size2) for (i=n; i < size3; i++) { *(v3[0]+i) = 0.0; *(v3[1]+i) = 0.0; } return 0; }