/* Create the per pixel equation given the index, parameter, and general expression */
if ((per_pixel_eqn = new_per_pixel_eqn(index, param, gen_expr)) == NULL) {
if (PER_PIXEL_EQN_DEBUG) printf("add_per_pixel_eqn: failed to create new per pixel equation!\n");
/* Create the per pixel equation given the index, parameter, and general expression */
if ((per_pixel_eqn = new_per_pixel_eqn(index, param, gen_expr)) == NULL) {
if (PER_PIXEL_EQN_DEBUG) printf("add_per_pixel_eqn: failed to create new per pixel equation!\n");