Initial commit

libs/math/example/policy_eg_7.cpp

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+//  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;
+#include <cerrno> // for ::errno
+
+//[policy_eg_7
+
+#include <boost/math/distributions.hpp> // All distributions.
+// using boost::math::normal; // Would create an ambguity between
+// boost::math::normal_distribution<RealType> boost::math::normal and
+// 'anonymous-namespace'::normal'.
+
+namespace
+{ // anonymous or unnnamed (rather than named as in policy_eg_6.cpp).
+
+  using namespace boost::math::policies;
+   // using boost::math::policies::errno_on_error; // etc.
+  typedef policy<
+     // return infinity and set errno rather than throw:
+     overflow_error<errno_on_error>,
+     // Don't promote double -> long double internally:
+     promote_double<false>,
+     // Return the closest integer result for discrete quantiles:
+     discrete_quantile<integer_round_nearest>
+  > my_policy;
+
+  BOOST_MATH_DECLARE_DISTRIBUTIONS(double, my_policy)
+
+} // close namespace my_namespace
+
+int main()
+{
+   // Construct distribution with something we know will overflow.
+   normal norm(10, 2); // using 'anonymous-namespace'::normal
+   errno = 0;
+   cout << "Result of quantile(norm, 0) is: " 
+      << quantile(norm, 0) << endl;
+   cout << "errno = " << errno << endl;
+   errno = 0;
+   cout << "Result of quantile(norm, 1) is: " 
+      << quantile(norm, 1) << endl;
+   cout << "errno = " << errno << endl;
+   //
+   // Now try a discrete distribution:
+   binomial binom(20, 0.25);
+   cout << "Result of quantile(binom, 0.05) is: " 
+      << quantile(binom, 0.05) << endl;
+   cout << "Result of quantile(complement(binom, 0.05)) is: " 
+      << quantile(complement(binom, 0.05)) << endl;
+}
+
+//] //[/policy_eg_7]
+
+/*
+
+Output:
+
+  Result of quantile(norm, 0) is: -1.#INF
+  errno = 34
+  Result of quantile(norm, 1) is: 1.#INF
+  errno = 34
+  Result of quantile(binom, 0.05) is: 1
+  Result of quantile(complement(binom, 0.05)) is: 8
+
+*/