Package weka.core.matrix
Class Maths
java.lang.Object
weka.core.matrix.Maths
- All Implemented Interfaces:
RevisionHandler
Utility class.
Adapted from the JAMA package.
- Version:
- $Revision: 5953 $
- Author:
- The Mathworks and NIST, Fracpete (fracpete at waikato dot ac dot nz)
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final intDistribution type: chi-squaredstatic final doubleThe constant - log( sqrt(2 pi) )static final intDistribution type: noramlstatic final doubleThe constant 1 / sqrt(2 pi)static final intDistribution type: undefined -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic doubledchisq(double x) Returns the density of the Chi-squared distribution.static doubledchisq(double x, double ncp) Returns the density of the noncentral Chi-squared distribution.static DoubleVectordchisq(double x, DoubleVector ncp) Returns the density of the noncentral Chi-squared distribution.static doubledchisqLog(double x) Returns the log-density of the noncentral Chi-square distribution.static doubledchisqLog(double x, double ncp) Returns the log-density value of a noncentral Chi-square distribution.static DoubleVectordchisqLog(double x, DoubleVector ncp) Returns the log-density of a set of noncentral Chi-squared distributions.static doublednorm(double x) Returns the density of the standard normal.static doublednorm(double x, double mean, double sd) Returns the density value of a standard normal.static DoubleVectordnorm(double x, DoubleVector mean, double sd) Returns the density values of a set of normal distributions with different means.static doublednormLog(double x) Returns the log-density of the standard normal.static doublednormLog(double x, double mean, double sd) Returns the log-density value of a standard normal.static DoubleVectordnormLog(double x, DoubleVector mean, double sd) Returns the log-density values of a set of normal distributions with different means.Returns the revision string.static doublehypot(double a, double b) sqrt(a^2 + b^2) without under/overflow.static doublepchisq(double x) Returns the cumulative probability of the Chi-squared distributionstatic doublepchisq(double x, double ncp) Returns the cumulative probability of the noncentral Chi-squared distribution.static DoubleVectorpchisq(double x, DoubleVector ncp) Returns the cumulative probability of a set of noncentral Chi-squared distributions.static doublepnorm(double x) Returns the cumulative probability of the standard normal.static doublepnorm(double x, double mean, double sd) Returns the cumulative probability of a normal distribution.static DoubleVectorpnorm(double x, DoubleVector mean, double sd) Returns the cumulative probability of a set of normal distributions with different means.static DoubleVectorGenerates a sample of a Chi-square distribution.static DoubleVectorGenerates a sample of a normal distribution.static doublesquare(double x) Returns the square of a value
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Field Details
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PSI
public static final double PSIThe constant 1 / sqrt(2 pi)- See Also:
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logPSI
public static final double logPSIThe constant - log( sqrt(2 pi) )- See Also:
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undefinedDistribution
public static final int undefinedDistributionDistribution type: undefined- See Also:
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normalDistribution
public static final int normalDistributionDistribution type: noraml- See Also:
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chisqDistribution
public static final int chisqDistributionDistribution type: chi-squared- See Also:
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Constructor Details
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Maths
public Maths()
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Method Details
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hypot
public static double hypot(double a, double b) sqrt(a^2 + b^2) without under/overflow. -
square
public static double square(double x) Returns the square of a value- Parameters:
x-- Returns:
- the square
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pnorm
public static double pnorm(double x) Returns the cumulative probability of the standard normal.- Parameters:
x- the quantile
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pnorm
public static double pnorm(double x, double mean, double sd) Returns the cumulative probability of a normal distribution.- Parameters:
x- the quantilemean- the mean of the normal distributionsd- the standard deviation of the normal distribution.
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pnorm
Returns the cumulative probability of a set of normal distributions with different means.- Parameters:
x- the vector of quantilesmean- the means of the normal distributionssd- the standard deviation of the normal distribution.- Returns:
- the cumulative probability
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dnorm
public static double dnorm(double x) Returns the density of the standard normal.- Parameters:
x- the quantile- Returns:
- the density
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dnorm
public static double dnorm(double x, double mean, double sd) Returns the density value of a standard normal.- Parameters:
x- the quantilemean- the mean of the normal distributionsd- the standard deviation of the normal distribution.- Returns:
- the density
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dnorm
Returns the density values of a set of normal distributions with different means.- Parameters:
x- the quantilemean- the means of the normal distributionssd- the standard deviation of the normal distribution.- Returns:
- the density
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dnormLog
public static double dnormLog(double x) Returns the log-density of the standard normal.- Parameters:
x- the quantile- Returns:
- the density
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dnormLog
public static double dnormLog(double x, double mean, double sd) Returns the log-density value of a standard normal.- Parameters:
x- the quantilemean- the mean of the normal distributionsd- the standard deviation of the normal distribution.- Returns:
- the density
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dnormLog
Returns the log-density values of a set of normal distributions with different means.- Parameters:
x- the quantilemean- the means of the normal distributionssd- the standard deviation of the normal distribution.- Returns:
- the density
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rnorm
Generates a sample of a normal distribution.- Parameters:
n- the size of the samplemean- the mean of the normal distributionsd- the standard deviation of the normal distribution.random- the random stream- Returns:
- the sample
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pchisq
public static double pchisq(double x) Returns the cumulative probability of the Chi-squared distribution- Parameters:
x- the quantile
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pchisq
public static double pchisq(double x, double ncp) Returns the cumulative probability of the noncentral Chi-squared distribution.- Parameters:
x- the quantilencp- the noncentral parameter
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pchisq
Returns the cumulative probability of a set of noncentral Chi-squared distributions.- Parameters:
x- the quantilencp- the noncentral parameters
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dchisq
public static double dchisq(double x) Returns the density of the Chi-squared distribution.- Parameters:
x- the quantile- Returns:
- the density
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dchisq
public static double dchisq(double x, double ncp) Returns the density of the noncentral Chi-squared distribution.- Parameters:
x- the quantilencp- the noncentral parameter
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dchisq
Returns the density of the noncentral Chi-squared distribution.- Parameters:
x- the quantilencp- the noncentral parameters
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dchisqLog
public static double dchisqLog(double x) Returns the log-density of the noncentral Chi-square distribution.- Parameters:
x- the quantile- Returns:
- the density
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dchisqLog
public static double dchisqLog(double x, double ncp) Returns the log-density value of a noncentral Chi-square distribution.- Parameters:
x- the quantilencp- the noncentral parameter- Returns:
- the density
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dchisqLog
Returns the log-density of a set of noncentral Chi-squared distributions.- Parameters:
x- the quantilencp- the noncentral parameters
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rchisq
Generates a sample of a Chi-square distribution.- Parameters:
n- the size of the samplencp- the noncentral parameterrandom- the random stream- Returns:
- the sample
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getRevision
Returns the revision string.- Specified by:
getRevisionin interfaceRevisionHandler- Returns:
- the revision
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