Quantile functions in boost (C++)

Grzenio picture Grzenio · Apr 6, 2011 · Viewed 13.2k times · Source

Judging from the documentation boost seems to offer quantile functions (inverse cdf functions) for both normal and gamma distributions, but its not clear for me how can I actually use them. Could someone paste an example please?

Answer

Inverse picture Inverse · Apr 6, 2011

The quantile calculation is implemented as a free function. Here's an example:

#include <boost/math/distributions/normal.hpp>

boost::math::normal dist(0.0, 1.0);

// 95% of distribution is below q:
double q = quantile(dist, 0.95);

You can also get the complement (quantile from the right) using:

// 95% of distribution is above qc:
double qc = quantile(complement(dist, 0.05));

There are some similar worked examples here:

http://www.boost.org/doc/libs/1_46_1/libs/math/doc/sf_and_dist/html/math_toolkit/dist/stat_tut/weg.html

Edit: don't need namespaces on the free functions thanks to ADL