Package edu.cmu.tetrad.search.utils

Class TetradTestDiscrete

java.lang.Object

edu.cmu.tetrad.search.utils.TetradTestDiscrete

All Implemented Interfaces:

TetradTest

public final class TetradTestDiscrete
extends Object
implements TetradTest

Implements a test of tetrad constraints with discrete variables. We are assuming that variables are ordinal or binary. Such tests are a core statistical procedure in algorithm BuildPureClusters and Purify. An "underlying latent variable" approach is used to test tetrads indirectly by fitting discrete one-factor and two-factor models. See Bartholomew and Knott (1999) for details. A two-stage procedure for fitting polychorics correlations (Olsson, 1979) and a chi-square test of tetrad constraints over those correlations is the key for this method. References: Bartholomew, D. and Knott, M. (1999). Latent Variable Models and Factor Analysis, 2nd edition. Arnold. Olsson, Ulf (1979). "Maximum likelihood estimation of the polychoric correlation coefficient". Psychometrika 44, 443-460. Stroud, A. and Secrest D. (1966) Gaussian Quadrature Formulas. Prentice Hall.

Version:

$Id: $Id

Author:

Ricardo Silva

Field Summary

Fields

Modifier and Type	Field	Description
boolean	verbose	Whether to print out verbose information.

Constructor Summary

Constructors

Constructor	Description
TetradTestDiscrete(DataSet dataSet, double sig)	Constructor for TetradTestDiscrete.

Method Summary

Modifier and Type	Method	Description
ICovarianceMatrix	getCovMatrix()	getCovMatrix.
DataSet	getDataSet()	Getter for the field dataSet.
double	getSignificance()	getSignificance.
List<Node>	getVariables()	getVariables.
String[]	getVarNames()	getVarNames.
boolean	oneFactorTest(int i, int j, int k, int l)	oneFactorTest.
boolean	oneFactorTest(int i, int j, int k, int l, int x)	oneFactorTest.
void	resetCache()	resetCache.
void	setSignificance(double sig)	setSignificance.
boolean	tetradHolds(int i, int j, int k, int l)	tetradHolds.
double	tetradPValue(int v1, int v2, int v3, int v4)	tetradPValue.
int	tetradScore(int i, int j, int k, int l)	tetradScore.
boolean	tetradScore1(int v1, int v2, int v3, int v4)	tetradScore1.
boolean	tetradScore3(int v1, int v2, int v3, int v4)	tetradScore3.
boolean	twoFactorTest(int i, int j, int k, int l)	twoFactorTest.
boolean	twoFactorTest(int i, int j, int k, int l, int x)	twoFactorTest.
boolean	twoFactorTest(int i, int j, int k, int l, int x, int y)	twoFactorTest.

Methods inherited from class java.lang.Object

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

Field Details

verbose

public boolean verbose

Whether to print out verbose information.

Constructor Details

TetradTestDiscrete

public TetradTestDiscrete(DataSet dataSet,
 double sig)

Constructor for TetradTestDiscrete.

Parameters:

dataSet - a DataSet object

sig - a double

Method Details

getVarNames

public String[] getVarNames()

getVarNames.

Specified by:

getVarNames in interface TetradTest

Returns:

an array of String objects

getVariables

public List<Node> getVariables()

getVariables.

Specified by:

getVariables in interface TetradTest

Returns:

a List object

getDataSet

public DataSet getDataSet()

Getter for the field dataSet.

Specified by:

getDataSet in interface TetradTest

Returns:

a DataSet object

resetCache

public void resetCache()

resetCache.

getSignificance

public double getSignificance()

getSignificance.

Specified by:

getSignificance in interface TetradTest

Returns:

a double

setSignificance

public void setSignificance(double sig)

setSignificance.

Specified by:

setSignificance in interface TetradTest

Parameters:

sig - a double

tetradScore

public int tetradScore(int i,
 int j,
 int k,
 int l)

tetradScore.

Specified by:

tetradScore in interface TetradTest

Parameters:

i - a int

j - a int

k - a int

l - a int

Returns:

a int

tetradScore1

public boolean tetradScore1(int v1,
 int v2,
 int v3,
 int v4)

tetradScore1.

Tests the tetrad (v1, v3) x (v2, v4) = (v1, v4) x (v2, v3), and only that.

Specified by:

tetradScore1 in interface TetradTest

Parameters:

v1 - a int

v2 - a int

v3 - a int

v4 - a int

Returns:

a boolean

tetradScore3

public boolean tetradScore3(int v1,
 int v2,
 int v3,
 int v4)

tetradScore3.

Tests if all tetrad constraints hold

Specified by:

tetradScore3 in interface TetradTest

Parameters:

v1 - a int

v2 - a int

v3 - a int

v4 - a int

Returns:

a boolean

tetradPValue

public double tetradPValue(int v1,
 int v2,
 int v3,
 int v4)

tetradPValue.

Specified by:

tetradPValue in interface TetradTest

Parameters:

v1 - a int

v2 - a int

v3 - a int

v4 - a int

Returns:

a double

tetradHolds

public boolean tetradHolds(int i,
 int j,
 int k,
 int l)

tetradHolds.

Specified by:

tetradHolds in interface TetradTest

Parameters:

i - a int

j - a int

k - a int

l - a int

Returns:

a boolean

oneFactorTest

public boolean oneFactorTest(int i,
 int j,
 int k,
 int l)

oneFactorTest.

Specified by:

oneFactorTest in interface TetradTest

Parameters:

i - a int

j - a int

k - a int

l - a int

Returns:

a boolean

oneFactorTest

public boolean oneFactorTest(int i,
 int j,
 int k,
 int l,
 int x)

oneFactorTest.

Specified by:

oneFactorTest in interface TetradTest

Parameters:

i - a int

j - a int

k - a int

l - a int

x - a int

Returns:

a boolean

twoFactorTest

public boolean twoFactorTest(int i,
 int j,
 int k,
 int l)

twoFactorTest.

Specified by:

twoFactorTest in interface TetradTest

Parameters:

i - a int

j - a int

k - a int

l - a int

Returns:

a boolean

twoFactorTest

public boolean twoFactorTest(int i,
 int j,
 int k,
 int l,
 int x)

twoFactorTest.

Specified by:

twoFactorTest in interface TetradTest

Parameters:

i - a int

j - a int

k - a int

l - a int

x - a int

Returns:

a boolean

twoFactorTest

public boolean twoFactorTest(int i,
 int j,
 int k,
 int l,
 int x,
 int y)

twoFactorTest.

Specified by:

twoFactorTest in interface TetradTest

Parameters:

i - a int

j - a int

k - a int

l - a int

x - a int

y - a int

Returns:

a boolean

getCovMatrix

public ICovarianceMatrix getCovMatrix()

getCovMatrix.

Specified by:

getCovMatrix in interface TetradTest

Returns:

a ICovarianceMatrix object