.TH "mlpack::distribution::DiscreteDistribution" 3 "Tue Sep 9 2014" "Version 1.0.10" "MLPACK" \" -*- nroff -*-
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.SH NAME
mlpack::distribution::DiscreteDistribution \- 
.PP
A discrete distribution where the only observations are discrete observations\&.  

.SH SYNOPSIS
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.PP
.SS "Public Member Functions"

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.RI "\fBDiscreteDistribution\fP ()"
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.RI "\fIDefault constructor, which creates a distribution that has no observations\&. \fP"
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.RI "\fBDiscreteDistribution\fP (const size_t numObservations)"
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.RI "\fIDefine the discrete distribution as having numObservations possible observations\&. \fP"
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.RI "\fBDiscreteDistribution\fP (const arma::vec &\fBprobabilities\fP)"
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.RI "\fIDefine the discrete distribution as having the given probabilities for each observation\&. \fP"
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.RI "size_t \fBDimensionality\fP () const "
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.RI "\fIGet the dimensionality of the distribution\&. \fP"
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.RI "void \fBEstimate\fP (const arma::mat &observations)"
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.RI "\fIEstimate the probability distribution directly from the given observations\&. \fP"
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.RI "void \fBEstimate\fP (const arma::mat &observations, const arma::vec &\fBprobabilities\fP)"
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.RI "\fIEstimate the probability distribution from the given observations, taking into account the probability of each observation actually being from this distribution\&. \fP"
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.RI "const arma::vec & \fBProbabilities\fP () const "
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.RI "\fIReturn the vector of probabilities\&. \fP"
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.RI "arma::vec & \fBProbabilities\fP ()"
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.RI "\fIModify the vector of probabilities\&. \fP"
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.RI "double \fBProbability\fP (const arma::vec &observation) const "
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.RI "\fIReturn the probability of the given observation\&. \fP"
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.RI "arma::vec \fBRandom\fP () const "
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.RI "\fIReturn a randomly generated observation (one-dimensional vector; one observation) according to the probability distribution defined by this object\&. \fP"
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.RI "std::string \fBToString\fP () const "
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.SS "Private Attributes"

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.RI "arma::vec \fBprobabilities\fP"
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.SH "Detailed Description"
.PP 
A discrete distribution where the only observations are discrete observations\&. 

This is useful (for example) with discrete Hidden Markov Models, where observations are non-negative integers representing specific emissions\&.
.PP
No bounds checking is performed for observations, so if an invalid observation is passed (i\&.e\&. observation > numObservations), a crash will probably occur\&.
.PP
This distribution only supports one-dimensional observations, so when passing an arma::vec as an observation, it should only have one dimension (vec\&.n_rows == 1)\&. Any additional dimensions will simply be ignored\&.
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\fBNote:\fP
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This class, like every other class in MLPACK, uses arma::vec to represent observations\&. While a discrete distribution only has positive integers (size_t) as observations, these can be converted to doubles (which is what arma::vec holds)\&. This distribution internally converts those doubles back into size_t before comparisons\&.  
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.PP
Definition at line 53 of file discrete_distribution\&.hpp\&.
.SH "Constructor & Destructor Documentation"
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.SS "mlpack::distribution::DiscreteDistribution::DiscreteDistribution ()\fC [inline]\fP"

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Default constructor, which creates a distribution that has no observations\&. 
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Definition at line 59 of file discrete_distribution\&.hpp\&.
.SS "mlpack::distribution::DiscreteDistribution::DiscreteDistribution (const size_tnumObservations)\fC [inline]\fP"

.PP
Define the discrete distribution as having numObservations possible observations\&. The probability in each state will be set to (1 / numObservations)\&.
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\fBParameters:\fP
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\fInumObservations\fP Number of possible observations this distribution can have\&. 
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Definition at line 69 of file discrete_distribution\&.hpp\&.
.SS "mlpack::distribution::DiscreteDistribution::DiscreteDistribution (const arma::vec &probabilities)\fC [inline]\fP"

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Define the discrete distribution as having the given probabilities for each observation\&. 
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\fBParameters:\fP
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\fIprobabilities\fP Probabilities of each possible observation\&. 
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.PP
Definition at line 79 of file discrete_distribution\&.hpp\&.
.SH "Member Function Documentation"
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.SS "size_t mlpack::distribution::DiscreteDistribution::Dimensionality () const\fC [inline]\fP"

.PP
Get the dimensionality of the distribution\&. 
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Definition at line 95 of file discrete_distribution\&.hpp\&.
.SS "void mlpack::distribution::DiscreteDistribution::Estimate (const arma::mat &observations)"

.PP
Estimate the probability distribution directly from the given observations\&. If any of the observations is greater than numObservations, a crash is likely to occur\&.
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\fBParameters:\fP
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\fIobservations\fP List of observations\&. 
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.SS "void mlpack::distribution::DiscreteDistribution::Estimate (const arma::mat &observations, const arma::vec &probabilities)"

.PP
Estimate the probability distribution from the given observations, taking into account the probability of each observation actually being from this distribution\&. 
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\fBParameters:\fP
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\fIobservations\fP List of observations\&. 
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\fIprobabilities\fP List of probabilities that each observation is actually from this distribution\&. 
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.SS "const arma::vec& mlpack::distribution::DiscreteDistribution::Probabilities () const\fC [inline]\fP"

.PP
Return the vector of probabilities\&. 
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Definition at line 153 of file discrete_distribution\&.hpp\&.
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References probabilities\&.
.SS "arma::vec& mlpack::distribution::DiscreteDistribution::Probabilities ()\fC [inline]\fP"

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Modify the vector of probabilities\&. 
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Definition at line 155 of file discrete_distribution\&.hpp\&.
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References probabilities\&.
.SS "double mlpack::distribution::DiscreteDistribution::Probability (const arma::vec &observation) const\fC [inline]\fP"

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Return the probability of the given observation\&. If the observation is greater than the number of possible observations, then a crash will probably occur -- bounds checking is not performed\&.
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\fBParameters:\fP
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\fIobservation\fP Observation to return the probability of\&. 
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\fBReturns:\fP
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Probability of the given observation\&. 
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Definition at line 105 of file discrete_distribution\&.hpp\&.
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References mlpack::Log::Debug, and probabilities\&.
.SS "arma::vec mlpack::distribution::DiscreteDistribution::Random () const"

.PP
Return a randomly generated observation (one-dimensional vector; one observation) according to the probability distribution defined by this object\&. 
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\fBReturns:\fP
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Random observation\&. 
.RE
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.SS "std::string mlpack::distribution::DiscreteDistribution::ToString () const"

.SH "Member Data Documentation"
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.SS "arma::vec mlpack::distribution::DiscreteDistribution::probabilities\fC [private]\fP"

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Definition at line 163 of file discrete_distribution\&.hpp\&.
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Referenced by Probabilities(), and Probability()\&.

.SH "Author"
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Generated automatically by Doxygen for MLPACK from the source code\&.