diff options
Diffstat (limited to 'src/boost/libs/math/example/policy_ref_snip11.cpp')
-rw-r--r-- | src/boost/libs/math/example/policy_ref_snip11.cpp | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/src/boost/libs/math/example/policy_ref_snip11.cpp b/src/boost/libs/math/example/policy_ref_snip11.cpp new file mode 100644 index 00000000..9e82750a --- /dev/null +++ b/src/boost/libs/math/example/policy_ref_snip11.cpp @@ -0,0 +1,45 @@ +// Copyright John Maddock 2007. +// Copyright Paul A. Bristow 2010 +// Use, modification and distribution are subject to the +// Boost Software License, Version 1.0. (See accompanying file +// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) + +// Note that this file contains quickbook mark-up as well as code +// and comments, don't change any of the special comment mark-ups! + +#include <iostream> +using std::cout; using std::endl; + +// Setting (approximate) precision 25 bits in a single function call using make_policy. + +//[policy_ref_snip11 + +#include <boost/math/distributions/normal.hpp> +using boost::math::normal_distribution; + +using namespace boost::math::policies; + +const int bits = 25; // approximate precision. + +double q = quantile( + normal_distribution<double, policy<digits2<bits> > >(), + 0.05); // 5% quantile. + +//] //[/policy_ref_snip11] + +int main() +{ + std::streamsize p = 2 + (bits * 30103UL) / 100000UL; + // Approximate number of significant decimal digits for 25 bits. + cout.precision(p); + cout << bits << " binary bits is approoximately equivalent to " << p << " decimal digits " << endl; + cout << "quantile(normal_distribution<double, policy<digits2<25> > >(), 0.05 = " + << q << endl; // -1.64485 +} + +/* +Output: + 25 binary bits is approoximately equivalent to 9 decimal digits + quantile(normal_distribution<double, policy<digits2<25> > >(), 0.05 = -1.64485363 + */ + |