for (double r2 = 0.0; r2 < 3000.0; r2 += step_size) {
double x = r2 + step_size*0.5;
double probscore = prob_score_real(a, prodai_precompute, (r1 - x)*winfac);
for (double r2 = 0.0; r2 < 3000.0; r2 += step_size) {
double x = r2 + step_size*0.5;
double probscore = prob_score_real(a, prodai_precompute, (r1 - x)*winfac);