quantile

double quantile(double* first, double* last, double q);

Returns the q * 100 percentile of the elements in [first, last).

Parameters:
firstBeginning iterator for the container of elements.
lastEnding iterator for the container of elements.
qQuantile to compute.

Returns:
q * 100 percentile

Usage:
double s[4] = {1.1, 2.2, 3.3, 4.4};
double q = quantile(s, s + 4, .95);

Header:
#include "descript.h"