Package edu.cmu.tetrad.sem

Class Parameter

java.lang.Object

edu.cmu.tetrad.sem.Parameter

All Implemented Interfaces:

TetradSerializable, Serializable

public final class Parameter
extends Object
implements TetradSerializable

Stores information about the identity of a SEM parameter--its name, its type (COEF, COVAR), and the node(s) it is associated with.

Version:

$Id: $Id

Author:

Don Crimbchin (djc2@andrew.cmu.edu), josephramsey

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
Parameter(String name, ParamType type, Node nodeA, Node nodeB)	Constructor for Parameter.

Method Summary

Modifier and Type	Method	Description
Distribution	getDistribution()	Getter for the field distribution.
String	getName()	Getter for the field name.
Node	getNodeA()	Getter for the field nodeA.
Node	getNodeB()	Getter for the field nodeB.
double	getStartingValue()	Getter for the field startingValue.
ParamType	getType()	Getter for the field type.
boolean	isFixed()	isFixed.
boolean	isInitializedRandomly()	isInitializedRandomly.
static Parameter	serializableInstance()	Generates a simple exemplar of this class to test serialization.
void	setDistribution(Distribution distribution)	Sets the distribution that initial values should be drawn from for this parameter.
void	setFixed(boolean fixed)	Sets whether this parameter should be held fixed during estimation.
void	setInitializedRandomly(boolean initializedRandomly)	Set to true iff this parameter should be initialized randomly by drawing an initial value from its preset random distribution.
void	setName(String name)	Sets the name for this parameter.
void	setStartingValue(double startingValue)	Sets the starting value in case this is a fixed parameter.
String	toString()	toString.

Methods inherited from class java.lang.Object

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

Constructor Details

Parameter

public Parameter(String name,
 ParamType type,
 Node nodeA,
 Node nodeB)

Constructor for Parameter.

Parameters:

name - The name of the parameter.

type - The type of the parameter--ParamType.COEF, ParamType.VAR, or ParamType.COVAR.

nodeA - The "from" node.

nodeB - The "to" node. (For variance freeParameters, this must be the same as the "from" node. For covariance freeParameters, it must be different from the "from" node.)

Method Details

serializableInstance

public static Parameter serializableInstance()

Generates a simple exemplar of this class to test serialization.

Returns:

a Parameter object

getName

public String getName()

Getter for the field name.

Returns:

the name of the parameter.

setName

public void setName(String name)

Sets the name for this parameter.

Parameters:

name - a String object

Throws:

IllegalArgumentException - if the name does not begin with a letter.

toString

public String toString()

toString.

Overrides:

toString in class Object

Returns:

a string representation for this parameter.

getNodeA

public Node getNodeA()

Getter for the field nodeA.

Returns:

the "from" node for the edge this parameter is associated with.

getNodeB

public Node getNodeB()

Getter for the field nodeB.

Returns:

the "to" node for the edge this parameter is associated with.

getType

public ParamType getType()

Getter for the field type.

Returns:

the type of this parameter--ParamType.COEF or ParamType.COVAR. This is set at construction time.

getDistribution

public Distribution getDistribution()

Getter for the field distribution.

Returns:

the distributions that initial values should be drawn from for this parameter.

setDistribution

public void setDistribution(Distribution distribution)

Sets the distribution that initial values should be drawn from for this parameter. To set the parameter to always use the same initial value, use tetrad.util.SingleValue.

Parameters:

distribution - a Distribution object

See Also:

• SingleValue

isFixed

public boolean isFixed()

isFixed.

Returns:

true iff this parameter should be held fixed during estimation.

setFixed

public void setFixed(boolean fixed)

Sets whether this parameter should be held fixed during estimation.

Parameters:

fixed - True if the parameter will be held fixed, false if not.

getStartingValue

public double getStartingValue()

Getter for the field startingValue.

Returns:

the starting value if this is a fixed parameter.

setStartingValue

public void setStartingValue(double startingValue)

Sets the starting value in case this is a fixed parameter.

Parameters:

startingValue - a double

isInitializedRandomly

public boolean isInitializedRandomly()

isInitializedRandomly.

Returns:

true iff this parameter should be initialized randomly by drawing an initial value from its preset random distribution.

setInitializedRandomly

public void setInitializedRandomly(boolean initializedRandomly)

Set to true iff this parameter should be initialized randomly by drawing an initial value from its preset random distribution.

Parameters:

initializedRandomly - a boolean