| Common mathematical functions | |||||||||||||||||||||||||||||||
| Mathematical special functions(C++17) | |||||||||||||||||||||||||||||||
| Mathematical constants(C++20) | |||||||||||||||||||||||||||||||
| Basic linear algebra algorithms(C++26) | |||||||||||||||||||||||||||||||
| Data-parallel types (SIMD)(C++26) | |||||||||||||||||||||||||||||||
| Floating-point environment(C++11) | |||||||||||||||||||||||||||||||
| Complex numbers | |||||||||||||||||||||||||||||||
Numeric array (valarray) | |||||||||||||||||||||||||||||||
| Pseudo-random number generation | |||||||||||||||||||||||||||||||
| Bit manipulation(C++20) | |||||||||||||||||||||||||||||||
| Saturation arithmetic(C++26) | |||||||||||||||||||||||||||||||
| Factor operations | |||||||||||||||||||||||||||||||
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| Interpolations | |||||||||||||||||||||||||||||||
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| Generic numeric operations | |||||||||||||||||||||||||||||||
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| C-style checked integer arithmetic | |||||||||||||||||||||||||||||||
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| Member functions | ||||
| Generation | ||||
| Characteristics | ||||
| Non-member functions | ||||
(C++11)(C++11)(until C++20) | ||||
(C++11)(C++11) |
Defined in header <random> | ||
template<class RealType=double> class piecewise_constant_distribution; | (since C++11) | |
std::piecewise_constant_distribution produces random floating-point numbers, which are uniformly distributed within each of the several subintervals[bi, bi+1), each with its own weightwi. The set of interval boundaries and the set of weights are the parameters of this distribution.
| wi |
| S (bi+1 - bi) |
std::piecewise_constant_distribution satisfies all requirements ofRandomNumberDistribution.
Contents |
| RealType | - | The result type generated by the generator. The effect is undefined if this is not one offloat,double, orlongdouble. |
| Member type | Definition |
result_type(C++11) | RealType |
param_type(C++11) | the type of the parameter set, seeRandomNumberDistribution. |
(C++11) | constructs new distribution (public member function)[edit] |
(C++11) | resets the internal state of the distribution (public member function)[edit] |
Generation | |
(C++11) | generates the next random number in the distribution (public member function)[edit] |
Characteristics | |
| returns the distribution parameters (public member function)[edit] | |
(C++11) | gets or sets the distribution parameter object (public member function)[edit] |
(C++11) | returns the minimum potentially generated value (public member function)[edit] |
(C++11) | returns the maximum potentially generated value (public member function)[edit] |
(C++11)(C++11)(removed in C++20) | compares two distribution objects (function)[edit] |
(C++11) | performs stream input and output on pseudo-random number distribution (function template)[edit] |
#include <iostream>#include <map>#include <random>#include <string> int main(){std::random_device rd;std::mt19937 gen(rd());// 50% of the time, generate a random number between 0 and 1// 50% of the time, generate a random number between 10 and 15std::vector<double> i{0,1,10,15};std::vector<double> w{1,0,1}; std::piecewise_constant_distribution<> d(i.begin(), i.end(), w.begin()); std::map<int,int> hist;for(int n{}; n<1e4;++n)++hist[d(gen)]; for(std::cout<<std::hex<<std::uppercase;auto[x, y]: hist)std::cout<< x<<' '<<std::string(y/100,'*')<<'\n';}
Possible output:
0 **************************************************A **********B *********C *********D **********E *********
