static void format_prob(char str_buf[10], double prob)
{

    if(prob > 0.9995) {
        snprintf(str_buf, 10, "100 %%");
    } else if(prob >= 0.1) {
        snprintf(str_buf, 10, "%4.1f %%", 100.0 * prob);
    } else {
        snprintf(str_buf, 10, " %3.1f %%", 100.0 * prob);
    }

    str_buf[9] = '\0';  //prevents _snprintf error
}