com.itemanalysis.psychometrics.distribution

Interface DistributionApproximation

All Known Implementing Classes:

AbstractDistributionApproximation, ContinuousDistributionApproximation, Histogram, KernelDensity, NormalDistributionApproximation, UniformDistributionApproximation, UserSuppliedDistributionApproximation

public interface DistributionApproximation

An interface for distribution approximations such as those used for quadrature points and weights in numeric integration. Each approximation has an array of evaluation points (x-axis) and an array of density values (y-axis). The minimum and maximum values and the number of evaluation points (and corresponding density values) are usually provided by the user.

Method Summary

Modifier and Type	Method and Description
double[]	evaluate() Gets and array of density values.
double	getDensityAt(int index) Gets an elements from the array of density values.
double	getMaximum()
double	getMean()
double	getMinimum()
int	getNumberOfPoints() Number of evaluation points (and corresponding number of density values) in this approximation.
double	getPointAt(int index) Gets an element from the array of evaluation points.
double[]	getPoints() Gets an array of evaluation points.
double	getStandardDeviation()
void	setDensityAt(int index, double density)
void	setPointAt(int index, double point)
double[]	standardize(boolean keepPoints)

Method Detail

getPoints

double[] getPoints()

Gets an array of evaluation points.

Returns:

evaluation points.

evaluate

double[] evaluate()

Gets and array of density values.

Returns:

density values.

getPointAt

double getPointAt(int index)

Gets an element from the array of evaluation points.

Parameters:

index - array index of evaluation points.

Returns:

evaluation point at index.

getDensityAt

double getDensityAt(int index)

Gets an elements from the array of density values.

Parameters:

index - array index of density value.

Returns:

density value at index.

getNumberOfPoints

int getNumberOfPoints()

Number of evaluation points (and corresponding number of density values) in this approximation.

Returns:

number of points.

setPointAt

void setPointAt(int index,
                double point)

setDensityAt

void setDensityAt(int index,
                  double density)

getMinimum

double getMinimum()

getMaximum

double getMaximum()

getMean

double getMean()

getStandardDeviation

double getStandardDeviation()

standardize

double[] standardize(boolean keepPoints)