a, ind, integral, trace->integral[ind + 1], trace->integral[ind],
trace->time_points[ind + 1], trace->time_points[ind]);
double_update(&a_aux, trace->time_points[ind]);
a, ind, integral, trace->integral[ind + 1], trace->integral[ind],
trace->time_points[ind + 1], trace->time_points[ind]);
double_update(&a_aux, trace->time_points[ind]);