weka.classifiers.m5
Class M5Utils

java.lang.Object
  |
  +--weka.classifiers.m5.M5Utils

public final class M5Utils

extends java.lang.Object

Class for some small methods used in M5Java

Author:

Yong Wang (yongwang@cs.waikato.ac.nz)

Constructor Summary

M5Utils()

Method Summary

static double	absDev(int attr, Instances inst) Returns the absolute deviation value of the instances values of an attribute
static double	correlation(double[] y1, double[] y2, int n) Returns the correlation coefficient of two double vectors
static java.lang.StringBuffer	deleteTrailingZerosAndDot(java.lang.StringBuffer stringBuffer) Deletes the trailing zeros and decimal point in a stringBuffer
static java.lang.String	doubleToStringF(double value, int width, int afterDecimalPoint) Rounds a double and converts it into a formatted right-justified String.
static java.lang.String	doubleToStringG(double value, int width, int precision) Rounds a double and converts it into a formatted right-justified String.
static boolean	eqDouble(double a, double b) Tests if two double values are equal to each other
static void	errorMsg(java.lang.String err) Prints error message and exits
static long	floorDouble(double value) Returns the largest (closest to positive infinity) long integer value that is not greater than the argument.
static boolean	hasEnumAttr(Instances inst) Tests if enumerated attribute(s) exists in the instances
static boolean	hasMissing(Instances inst) Tests if missing value(s) exists in the instances
static java.lang.String	headToString() Prints the head lines of the output
static long	roundDouble(double value) Rounds a double
static java.lang.String	separatorToString() Prints sepearating line
static double	smoothenValue(double p, double q, int n, int k) Returns the smoothed values according to the smoothing formula (np+kq)/(n+k)
static double	sqrSum(int attr, Instances inst) Returns the squared sum of the instances values of an attribute
static double	stdDev(int attr, Instances inst) Returns the standard deviation value of the instances values of an attribute
static double	sum(int attr, Instances inst) Returns the sum of the instances values of an attribute
static double	variance(int attr, Instances inst) Returns the variance value of the instances values of an attribute

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

M5Utils

public M5Utils()

Method Detail

hasEnumAttr

public static final boolean hasEnumAttr(Instances inst)

Tests if enumerated attribute(s) exists in the instances

Parameters:

inst - instances

Returns:

true if there is at least one; false if none

hasMissing

public static final boolean hasMissing(Instances inst)

Tests if missing value(s) exists in the instances

Parameters:

inst - instances

Returns:

true if there is missing value(s); false if none

sum

public static final double sum(int attr,
                               Instances inst)

Returns the sum of the instances values of an attribute

Parameters:

attr - an attribute

inst - instances

Returns:

the sum value

sqrSum

public static final double sqrSum(int attr,
                                  Instances inst)

Returns the squared sum of the instances values of an attribute

Parameters:

attr - an attribute

inst - instances

Returns:

the squared sum value

stdDev

public static final double stdDev(int attr,
                                  Instances inst)

Returns the standard deviation value of the instances values of an attribute

Parameters:

attr - an attribute

inst - instances

Returns:

the standard deviation value

absDev

public static final double absDev(int attr,
                                  Instances inst)

Returns the absolute deviation value of the instances values of an attribute

Parameters:

attr - an attribute

inst - instances

Returns:

the absolute deviation value

variance

public static final double variance(int attr,
                                    Instances inst)

Returns the variance value of the instances values of an attribute

Parameters:

attr - an attribute

inst - instances

Returns:

the variance value

roundDouble

public static final long roundDouble(double value)

Rounds a double

Parameters:

value - the double value

Returns:

the double rounded

floorDouble

public static final long floorDouble(double value)

Returns the largest (closest to positive infinity) long integer value that is not greater than the argument.

Parameters:

value - the double value

Returns:

the floor integer

doubleToStringF

public static final java.lang.String doubleToStringF(double value,
                                                     int width,
                                                     int afterDecimalPoint)

Rounds a double and converts it into a formatted right-justified String. It is like %f format in C language.

Parameters:

value - the double value

width - the width of the string

afterDecimalPoint - the number of digits after the decimal point

Returns:

the double as a formatted string

doubleToStringG

public static final java.lang.String doubleToStringG(double value,
                                                     int width,
                                                     int precision)

Rounds a double and converts it into a formatted right-justified String. If the double is not equal to zero and not in the range [10e-3,10e7] it is returned in scientific format. It is like %g format in C language.

Parameters:

value - the double value

width - the width of the string

precision - the number of valid digits

Returns:

the double as a formatted string

deleteTrailingZerosAndDot

public static final java.lang.StringBuffer deleteTrailingZerosAndDot(java.lang.StringBuffer stringBuffer)

Deletes the trailing zeros and decimal point in a stringBuffer

Parameters:

stringBuffer - string buffer return string buffer with deleted trailing zeros and decimal point

smoothenValue

public static final double smoothenValue(double p,
                                         double q,
                                         int n,
                                         int k)

Returns the smoothed values according to the smoothing formula (np+kq)/(n+k)

Parameters:

p - a double, normally is the prediction of the model at the current node

q - a double, normally is the prediction of the model at the up node

n - the number of instances at the up node

k - the smoothing constance, default =15

Returns:

the smoothed value

correlation

public static final double correlation(double[] y1,
                                       double[] y2,
                                       int n)

Returns the correlation coefficient of two double vectors

Parameters:

y1 - double vector 1

y2 - double vector 2

n - the length of two double vectors

Returns:

the correlation coefficient

eqDouble

public static final boolean eqDouble(double a,
                                     double b)

Tests if two double values are equal to each other

Parameters:

a - double 1

b - double 2

Returns:

true if equal; false if not equal

errorMsg

public static final void errorMsg(java.lang.String err)

Prints error message and exits

Parameters:

err - error message

separatorToString

public static final java.lang.String separatorToString()

Prints sepearating line

headToString

public static final java.lang.String headToString()

Prints the head lines of the output