/* PURPOSE: (Matrix transpose times matrix) ASSUMPTIONS AND LIMITATIONS: ((3x3 Matrix implementation)) PROGRAMMERS: (((Les Quiocho) (NASA/JSC) (Jan 1990) (v1.0) (Init Release))) */ #include "trick/trick_math.h" void dmtxm(double prod[3][3], /* Out: product of the two matrices */ double mat1[3][3], /* In: matrix 1 */ double mat2[3][3]) { /* In: matrix 2 */ double trans[3][3]; dm_trans(trans, mat1); prod[0][0] = trans[0][0] * mat2[0][0] + trans[0][1] * mat2[1][0] + trans[0][2] * mat2[2][0]; prod[0][1] = trans[0][0] * mat2[0][1] + trans[0][1] * mat2[1][1] + trans[0][2] * mat2[2][1]; prod[0][2] = trans[0][0] * mat2[0][2] + trans[0][1] * mat2[1][2] + trans[0][2] * mat2[2][2]; prod[1][0] = trans[1][0] * mat2[0][0] + trans[1][1] * mat2[1][0] + trans[1][2] * mat2[2][0]; prod[1][1] = trans[1][0] * mat2[0][1] + trans[1][1] * mat2[1][1] + trans[1][2] * mat2[2][1]; prod[1][2] = trans[1][0] * mat2[0][2] + trans[1][1] * mat2[1][2] + trans[1][2] * mat2[2][2]; prod[2][0] = trans[2][0] * mat2[0][0] + trans[2][1] * mat2[1][0] + trans[2][2] * mat2[2][0]; prod[2][1] = trans[2][0] * mat2[0][1] + trans[2][1] * mat2[1][1] + trans[2][2] * mat2[2][1]; prod[2][2] = trans[2][0] * mat2[0][2] + trans[2][1] * mat2[1][2] + trans[2][2] * mat2[2][2]; return; }