.TH "std::poisson_distribution< _IntType >" 3cxx "Tue Jul 2 2019" "libstdc++" \" -*- nroff -*-
.ad l
.nh
.SH NAME
std::poisson_distribution< _IntType > \- A discrete Poisson random number distribution\&.  

.SH SYNOPSIS
.br
.PP
.SS "Classes"

.in +1c
.ti -1c
.RI "struct \fBparam_type\fP"
.br
.in -1c
.SS "Public Types"

.in +1c
.ti -1c
.RI "typedef _IntType \fBresult_type\fP"
.br
.in -1c
.SS "Public Member Functions"

.in +1c
.ti -1c
.RI "\fBpoisson_distribution\fP (double __mean=1\&.0)"
.br
.ti -1c
.RI "\fBpoisson_distribution\fP (const \fBparam_type\fP &__p)"
.br
.ti -1c
.RI "template<typename _ForwardIterator , typename _UniformRandomNumberGenerator > void \fB__generate\fP (_ForwardIterator __f, _ForwardIterator __t, _UniformRandomNumberGenerator &__urng)"
.br
.ti -1c
.RI "template<typename _ForwardIterator , typename _UniformRandomNumberGenerator > void \fB__generate\fP (_ForwardIterator __f, _ForwardIterator __t, _UniformRandomNumberGenerator &__urng, const \fBparam_type\fP &__p)"
.br
.ti -1c
.RI "template<typename _UniformRandomNumberGenerator > void \fB__generate\fP (\fBresult_type\fP *__f, \fBresult_type\fP *__t, _UniformRandomNumberGenerator &__urng, const \fBparam_type\fP &__p)"
.br
.ti -1c
.RI "\fBresult_type\fP \fBmax\fP () const"
.br
.RI "Returns the least upper bound value of the distribution\&. "
.ti -1c
.RI "double \fBmean\fP () const"
.br
.RI "Returns the distribution parameter \fCmean\fP\&. "
.ti -1c
.RI "\fBresult_type\fP \fBmin\fP () const"
.br
.RI "Returns the greatest lower bound value of the distribution\&. "
.ti -1c
.RI "template<typename _UniformRandomNumberGenerator > \fBresult_type\fP \fBoperator()\fP (_UniformRandomNumberGenerator &__urng)"
.br
.RI "Generating functions\&. "
.ti -1c
.RI "template<typename _UniformRandomNumberGenerator > \fBresult_type\fP \fBoperator()\fP (_UniformRandomNumberGenerator &__urng, const \fBparam_type\fP &__p)"
.br
.ti -1c
.RI "\fBparam_type\fP \fBparam\fP () const"
.br
.RI "Returns the parameter set of the distribution\&. "
.ti -1c
.RI "void \fBparam\fP (const \fBparam_type\fP &__param)"
.br
.RI "Sets the parameter set of the distribution\&. "
.ti -1c
.RI "void \fBreset\fP ()"
.br
.RI "Resets the distribution state\&. "
.in -1c
.SS "Friends"

.in +1c
.ti -1c
.RI "template<typename _IntType1 , typename _CharT , typename _Traits > \fBstd::basic_ostream\fP< _CharT, _Traits > & \fBoperator<<\fP (\fBstd::basic_ostream\fP< _CharT, _Traits > &__os, const \fBstd::poisson_distribution\fP< _IntType1 > &__x)"
.br
.RI "Inserts a poisson_distribution random number distribution \fC__x\fP into the output stream \fC__os\fP\&. "
.ti -1c
.RI "bool \fBoperator==\fP (const \fBpoisson_distribution\fP &__d1, const \fBpoisson_distribution\fP &__d2)"
.br
.RI "Return true if two Poisson distributions have the same parameters and the sequences that would be generated are equal\&. "
.ti -1c
.RI "template<typename _IntType1 , typename _CharT , typename _Traits > \fBstd::basic_istream\fP< _CharT, _Traits > & \fBoperator>>\fP (\fBstd::basic_istream\fP< _CharT, _Traits > &__is, \fBstd::poisson_distribution\fP< _IntType1 > &__x)"
.br
.RI "Extracts a poisson_distribution random number distribution \fC__x\fP from the input stream \fC__is\fP\&. "
.in -1c
.SH "Detailed Description"
.PP 

.SS "template<typename _IntType = int>
.br
class std::poisson_distribution< _IntType >"
A discrete Poisson random number distribution\&. 

The formula for the Poisson probability density function is $p(i|\mu) = \frac{\mu^i}{i!} e^{-\mu}$ where $\mu$ is the parameter of the distribution\&. 
.PP
Definition at line 4330 of file random\&.h\&.
.SH "Member Typedef Documentation"
.PP 
.SS "template<typename _IntType = int> typedef _IntType \fBstd::poisson_distribution\fP< _IntType >::\fBresult_type\fP"
The type of the range of the distribution\&. 
.PP
Definition at line 4333 of file random\&.h\&.
.SH "Member Function Documentation"
.PP 
.SS "template<typename _IntType = int> \fBresult_type\fP \fBstd::poisson_distribution\fP< _IntType >::max () const\fC [inline]\fP"

.PP
Returns the least upper bound value of the distribution\&. 
.PP
Definition at line 4429 of file random\&.h\&.
.PP
References std::numeric_limits< _Tp >::max()\&.
.SS "template<typename _IntType = int> double \fBstd::poisson_distribution\fP< _IntType >::mean () const\fC [inline]\fP"

.PP
Returns the distribution parameter \fCmean\fP\&. 
.PP
Definition at line 4400 of file random\&.h\&.
.SS "template<typename _IntType = int> \fBresult_type\fP \fBstd::poisson_distribution\fP< _IntType >::min () const\fC [inline]\fP"

.PP
Returns the greatest lower bound value of the distribution\&. 
.PP
Definition at line 4422 of file random\&.h\&.
.SS "template<typename _IntType = int> template<typename _UniformRandomNumberGenerator > \fBresult_type\fP \fBstd::poisson_distribution\fP< _IntType >::operator() (_UniformRandomNumberGenerator & __urng)\fC [inline]\fP"

.PP
Generating functions\&. 
.PP
Definition at line 4437 of file random\&.h\&.
.SS "template<typename _IntType > template<typename _UniformRandomNumberGenerator > \fBpoisson_distribution\fP< _IntType >::\fBresult_type\fP \fBstd::poisson_distribution\fP< _IntType >::operator() (_UniformRandomNumberGenerator & __urng, const \fBparam_type\fP & __param)"
A rejection algorithm when mean >= 12 and a simple method based upon the multiplication of uniform random variates otherwise\&. NB: The former is available only if _GLIBCXX_USE_C99_MATH_TR1 is defined\&.
.PP
Reference: Devroye, L\&. Non-Uniform Random Variates Generation\&. Springer-Verlag, New York, 1986, Ch\&. X, Sects\&. 3\&.3 & 3\&.4 (+ Errata!)\&. 
.PP
Definition at line 1281 of file bits/random\&.tcc\&.
.PP
References std::abs(), std::numeric_limits< _Tp >::epsilon(), std::log(), and std::numeric_limits< _Tp >::max()\&.
.SS "template<typename _IntType = int> \fBparam_type\fP \fBstd::poisson_distribution\fP< _IntType >::param () const\fC [inline]\fP"

.PP
Returns the parameter set of the distribution\&. 
.PP
Definition at line 4407 of file random\&.h\&.
.SS "template<typename _IntType = int> void \fBstd::poisson_distribution\fP< _IntType >::param (const \fBparam_type\fP & __param)\fC [inline]\fP"

.PP
Sets the parameter set of the distribution\&. 
.PP
\fBParameters:\fP
.RS 4
\fI__param\fP The new parameter set of the distribution\&. 
.RE
.PP

.PP
Definition at line 4415 of file random\&.h\&.
.SS "template<typename _IntType = int> void \fBstd::poisson_distribution\fP< _IntType >::reset ()\fC [inline]\fP"

.PP
Resets the distribution state\&. 
.PP
Definition at line 4393 of file random\&.h\&.
.SH "Friends And Related Function Documentation"
.PP 
.SS "template<typename _IntType = int> template<typename _IntType1 , typename _CharT , typename _Traits > \fBstd::basic_ostream\fP<_CharT, _Traits>& operator<< (\fBstd::basic_ostream\fP< _CharT, _Traits > & __os, const \fBstd::poisson_distribution\fP< _IntType1 > & __x)\fC [friend]\fP"

.PP
Inserts a poisson_distribution random number distribution \fC__x\fP into the output stream \fC__os\fP\&. 
.PP
\fBParameters:\fP
.RS 4
\fI__os\fP An output stream\&. 
.br
\fI__x\fP A poisson_distribution random number distribution\&.
.RE
.PP
\fBReturns:\fP
.RS 4
The output stream with the state of \fC__x\fP inserted or in an error state\&. 
.RE
.PP

.SS "template<typename _IntType = int> bool operator== (const \fBpoisson_distribution\fP< _IntType > & __d1, const \fBpoisson_distribution\fP< _IntType > & __d2)\fC [friend]\fP"

.PP
Return true if two Poisson distributions have the same parameters and the sequences that would be generated are equal\&. 
.PP
Definition at line 4473 of file random\&.h\&.
.SS "template<typename _IntType = int> template<typename _IntType1 , typename _CharT , typename _Traits > \fBstd::basic_istream\fP<_CharT, _Traits>& operator>> (\fBstd::basic_istream\fP< _CharT, _Traits > & __is, \fBstd::poisson_distribution\fP< _IntType1 > & __x)\fC [friend]\fP"

.PP
Extracts a poisson_distribution random number distribution \fC__x\fP from the input stream \fC__is\fP\&. 
.PP
\fBParameters:\fP
.RS 4
\fI__is\fP An input stream\&. 
.br
\fI__x\fP A poisson_distribution random number generator engine\&.
.RE
.PP
\fBReturns:\fP
.RS 4
The input stream with \fC__x\fP extracted or in an error state\&. 
.RE
.PP


.SH "Author"
.PP 
Generated automatically by Doxygen for libstdc++ from the source code\&.