com.itemanalysis.psychometrics.scaling

Class DefaultLinearTransformation

java.lang.Object

com.itemanalysis.psychometrics.scaling.DefaultLinearTransformation

All Implemented Interfaces:

LinearTransformation

public class DefaultLinearTransformation
extends java.lang.Object
implements LinearTransformation

Author:

J. Patrick Meyer

Constructor Summary

Constructors

Constructor and Description
DefaultLinearTransformation()
DefaultLinearTransformation(double intercept, double scale)
DefaultLinearTransformation(java.lang.Double oldMean, java.lang.Double newMean, java.lang.Double oldSd, java.lang.Double newSd)
DefaultLinearTransformation(double oldMeanOrMin, double newMeanOrMin, double oldSdOrMax, double newSdOrMax, LinearTransformationType linearTransformationType) Constructor for two different ways of creating the transformation coefficients.

Method Summary

Modifier and Type	Method and Description
double	getIntercept()
double	getScale()
void	setIntercept(double intercept)
void	setScale(double scale)
void	setScaleAndIntercept(double oldMean, double newMean, double oldSd, double newSd)
java.lang.String	toString()
double	transform(double x)

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultLinearTransformation

public DefaultLinearTransformation(java.lang.Double oldMean,
                                   java.lang.Double newMean,
                                   java.lang.Double oldSd,
                                   java.lang.Double newSd)

DefaultLinearTransformation

public DefaultLinearTransformation(double oldMeanOrMin,
                                   double newMeanOrMin,
                                   double oldSdOrMax,
                                   double newSdOrMax,
                                   LinearTransformationType linearTransformationType)

Constructor for two different ways of creating the transformation coefficients. When linearTransformationType==MEAN_STANDARD_DEVIATION the transformation uses the new and old mean and standard deviation to compute the coefficients. When linearTransformationType==MIN_MAX the transformation uses the new and old min and max values t compute the transformation coefficients. The new mean and new standard deviation are the desired mean and standard deviation of the scale. Values will be transformed to have this mean and standard deviation. Likewise, the new min and new max are the desired minimum and desired maximum values of the scale. Original values will be transformed to have these min and max values.

Parameters:

oldMeanOrMin - either the old mean or the old minimum

newMeanOrMin - either the new mean or the new minimum

oldSdOrMax - either the old standard deviation or the old maximum

newSdOrMax - either the new standard deviation or the new maximum

linearTransformationType - method of computing the linear transformation

DefaultLinearTransformation

public DefaultLinearTransformation(double intercept,
                                   double scale)

DefaultLinearTransformation

public DefaultLinearTransformation()

Method Detail

setScale

public void setScale(double scale)

setScaleAndIntercept

public void setScaleAndIntercept(double oldMean,
                                 double newMean,
                                 double oldSd,
                                 double newSd)

setIntercept

public void setIntercept(double intercept)

getIntercept

public double getIntercept()

Specified by:

getIntercept in interface LinearTransformation

getScale

public double getScale()

Specified by:

getScale in interface LinearTransformation

transform

public double transform(double x)

Specified by:

transform in interface LinearTransformation

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object