class template
<random>

std::normal_distribution

`template <class RealType = double> class normal_distribution;`
Normal distribution
Random number distribution that produces floating-point values according to a normal distribution, which is described by the following probability density function:

This distribution produces random numbers around the distribution mean (μ) with a specific standard deviation (σ).

The normal distribution is a common distribution used for many kind of processes, since it is the distribution that the aggregation of a large number of independent random variables approximates to, when all follow the same distribution (no matter which distribution).

The distribution parameters, mean (μ) and stddev (σ), are set on construction.

To produce a random value following this distribution, call its member function operator().

Template parameters

RealType
A floating-point type. Aliased as member type result_type.
By default, this is double.

Member types

The following aliases are member types of normal_distribution:

member typedefinitionnotes
result_typeThe first template parameter (RealType)The type of the numbers generated (defaults to double)
param_typenot specifiedThe type returned by member param.

Example

 ``1234567891011121314151617181920212223242526272829`` ``````// normal_distribution #include #include #include int main() { const int nrolls=10000; // number of experiments const int nstars=100; // maximum number of stars to distribute std::default_random_engine generator; std::normal_distribution distribution(5.0,2.0); int p[10]={}; for (int i=0; i=0.0)&&(number<10.0)) ++p[int(number)]; } std::cout << "normal_distribution (5.0,2.0):" << std::endl; for (int i=0; i<10; ++i) { std::cout << i << "-" << (i+1) << ": "; std::cout << std::string(p[i]*nstars/nrolls,'*') << std::endl; } return 0; }``````

Possible output:
 ```normal_distribution (5.0,2.0): 0-1: * 1-2: **** 2-3: ********* 3-4: *************** 4-5: ****************** 5-6: ******************* 6-7: *************** 7-8: ******** 8-9: **** 9-10: * ```