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math/example/negative_binomial_construction_examples.cpp
Paul A. Bristow cbc6f2f44f update for new example using policies
[SVN r38646]
2007-08-14 08:41:13 +00:00

99 lines
4.2 KiB
C++

NOte now obselete - see deistribution_construction.cpp
// negative_binomial_example2.cpp
// Copyright Paul A. Bristow 2007.
// 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)
// Example 2 of using constructing distributions, shown here for negative_binomial.
#include <boost/math/distributions/negative_binomial.hpp> // for negative_binomial_distribution
using boost::math::negative_binomial_distribution; // default type is double.
using boost::math::negative_binomial; // typedef provides default type is double.
#include <boost/math/distributions/binomial.hpp> // for negative_binomial_distribution
#include <iostream>
using std::cout;
using std::endl;
int main()
{
// Several examples of constructing distributions, for example, negative binomial:
// A negative binomial with 8 successes and a success fraction 0.25, 25% or 1 in 4 is constructed like this:
boost::math::negative_binomial_distribution<double> mydist0(8., 0.25);
// But this is inconveniently long.
// The prefix boost::math:: can be avoided by
using boost::math::negative_binomial_distribution;
// Allows convenient reference to negative_binomial_distribution.
negative_binomial_distribution<> mydist9(8., 0.25); // Uses default RealType = double.
// But the name "negative_binomial_distribution" is still inconveniently long,
// so for most distributions, a typedef is provided, for example:
// typedef negative_binomial_distribution<double> negative_binomial; // Reserved name of type double.
using boost::math::negative_binomial; // Allows convenient access to the name negative_binomial.
// Some examples using the provided typedef:
// Allows convenient reference to negative_binomial of default type double.
negative_binomial mydist10(5., 0.4); // Both arguments double.
// And automatic conversion takes place, so you can use integers and floats:
negative_binomial mydist11(5, 0.4); // Using provided typedef double, int and double arguments.
// This is probably the most common usage.
negative_binomial mydist12(5., 0.4F); // Double and float arguments.
negative_binomial mydist13(5, 1); // Both arguments integer.
// But for cases when the typdef distribution name
// would clash with a math special function
// (for example binomial, beta and gamma)
// the typedef is deliberately not provided, and
// the longer version(s) must be used.
// For example:
using namespace boost::math;
// NOT binomial myb010(1, 0.5); but
binomial_distribution<> myb1(1, 0.5);
// You can also provide the type RealType explicitly thus:
negative_binomial_distribution<double> mydist1(8., 0.25); // Explicit double.
negative_binomial_distribution<float> mydist2(8., 0.25); // Explicit float, double arguments -> float.
negative_binomial_distribution<float> mydist3(8, 0.25); // Explicit float, integer & double arguments -> float.
negative_binomial_distribution<float> mydist4(8.F, 0.25F); // Explicit float, float arguments, no conversion.
negative_binomial_distribution<float> mydist5(8, 1); // Explicit integer, integer arguments -> float.
negative_binomial_distribution<double> mydist6(8., 0.25); // Explicit double.
negative_binomial_distribution<long double> mydist7(8., 0.25); // Explicit long double.
// And if you have your own RealType called MyFPType,
// for example NTL quad_float (128-bit floating-point), then:
// negative_binomial_distribution<MyFPType> mydist6(8, 1); // Integer arguments -> MyFPType.
// Note that default constructor arguments are only provided for some distributions.
// negative_binomial_distribution<> mydist;
// error C2512 no appropriate default constructor available.
// Since there are no accessor functions, no default constructor are provided,
// because it is difficult to chose any sensible default values for this distribution.
// For other distribution, like the normal distribution,
// it is obviously very useful to provide
// defaults for the mean and standard deviation thus:
// normal_distribution(RealType mean = 0, RealType sd = 1)
return 0;
} // int main()
/*
*/