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// piecewise_constant_distribution constructor
#include <iostream>
#include <chrono>
#include <random>
#include <array>
double square (double val) {return val*val;}
class accumulator {
double x;
public:
accumulator() :x(0.0) {}
double operator()(double val) {return x+=val;}
};
int main()
{
// construct a trivial random generator engine from a time-based seed:
unsigned seed = std::chrono::system_clock::now().time_since_epoch().count();
std::default_random_engine generator (seed);
std::array<double,5> intervals {0.0, 10.0, 20.0, 30.0, 40.0};
std::array<double,4> weights {1.0, 2.0, 3.0, 4.0};
typedef std::piecewise_constant_distribution<double> distribution_type;
distribution_type first;
distribution_type second (intervals.begin(), intervals.end(), weights.begin());
distribution_type third ( {0.0, 10.0, 15.0, 20.0, 22.0}, square );
distribution_type fourth ( 4, 0.0, 10.0, accumulator() );
distribution_type fifth (fourth.param());
std::cout << "displaying characteristics of fifth:" << std::endl;
std::cout << "intervals: ";
for (double x:fifth.intervals()) std::cout << x << " ";
std::cout << std::endl;
std::cout << "densities: ";
for (double x:fifth.densities()) std::cout << x << " ";
std::cout << std::endl;
return 0;
}
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