Inference (LBJava 1.2.22 API)

java.lang.Object
- edu.illinois.cs.cogcomp.lbjava.infer.Inference

Direct Known Subclasses:

ILPInference
```
public abstract class Inference
extends Object
```
An object of this class keeps track of all the information necessary to perform inference. Once that inference has been performed, constrained classifiers access the results through this class's interface to determine what their constrained predictions are.

Author:

Nick Rizzolo

Field Summary

Fields
Modifier and Type	Field and Description
`protected Constraint`	`constraint` The constraints which must be satisfied by the inference algorithm.
`protected Object`	`head` Objects of this class are differentiated by their "head" objects.
`protected LinkedHashMap`	`variables` The values of this map are the variables we perform inference over; they are the actual `FirstOrderVariable` objects found in this inference's constraints.

Constructor Summary

Constructors
Constructor and Description

Inference()
Default constructor.

Inference(Object h)
Initializes the head object.

Constructors
Constructor and Description
`Inference()` Default constructor.
`Inference(Object h)` Initializes the head object.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`static String`	`exampleToString(Object example)` Produces a string representation of an example object.
`Object`	`getHead()` Retrieves the head object.
`String[]`	`getHeadFinderTypes()` Returns the fully qualified names of the types of objects for which head finder methods have been defined.
`String`	`getHeadType()` Returns the fully qualified name of the type of the head object for this inference.
`Normalizer`	`getNormalizer(Learner c)` Returns the normalization function associated with the given classifier in this inference.
`FirstOrderVariable`	`getVariable(FirstOrderVariable v)` Retrieves the requested variable, creating it first if it doesn't yet exist.
`PropositionalVariable`	`getVariable(PropositionalVariable v)` Retrieves the requested variable, creating it first if it doesn't yet exist.
`protected abstract void`	`infer()` Derived classes implement this method to perform the inference, setting the values of the variables such that they maximize the objective function while satisfying the constraints.
`boolean`	`satisfied()` Determines if the constraints are satisfied by the current variable assignments.
`abstract String`	`valueOf(Learner c, Object o)` Retrieves the value of the specified variable as identified by the classifier and the object that produce that variable.
`void`	`visit(AtLeastQuantifier c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(AtMostQuantifier c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(ExistentialQuantifier c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(FirstOrderConjunction c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(FirstOrderConstant c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(FirstOrderDisjunction c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(FirstOrderDoubleImplication c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(FirstOrderEqualityTwoValues c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(FirstOrderEqualityWithValue c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(FirstOrderEqualityWithVariable c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(FirstOrderImplication c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(FirstOrderNegation c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(PropositionalAtLeast c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(PropositionalConjunction c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(PropositionalConstant c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(PropositionalDisjunction c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(PropositionalDoubleImplication c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(PropositionalImplication c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(PropositionalNegation c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(PropositionalVariable c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(QuantifiedConstraintInvocation c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visit(UniversalQuantifier c)` Derived classes override this method to do some type of processing on constraints of the parameter's type.
`void`	`visitAll(Constraint c)` The default method for visiting a constraint simply visits that constraint's children.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - variables
```
protected LinkedHashMap variables
```
    The values of this map are the variables we perform inference over; they are the actual FirstOrderVariable objects found in this inference's constraints. The keys are also objects of type FirstOrderVariable, but they are not necessarily the actual objects found in the constraints. This map is populated by the first evaluation of the constraints.
  - constraint
```
protected Constraint constraint
```
    The constraints which must be satisfied by the inference algorithm.
  - head
```
protected Object head
```
    Objects of this class are differentiated by their "head" objects.
- Constructor Detail
  - Inference
```
public Inference()
```
    Default constructor.
  - Inference
```
public Inference(Object h)
```
    Initializes the head object.
    
    Parameters:
    
    h - The head object.
- Method Detail
  - exampleToString
```
public static String exampleToString(Object example)
```
    Produces a string representation of an example object. This method is used mainly for debugging messages.
    
    Parameters:
    
    example - The example object, which may be an array.
    
    Returns:
    
    A string representation of example.
  - getHead
```
public Object getHead()
```
    Retrieves the head object.
  - infer
```
protected abstract void infer()
                       throws Exception
```
    Derived classes implement this method to perform the inference, setting the values of the variables such that they maximize the objective function while satisfying the constraints. When implementing this method in a derived class Foo, it may be assumed that the constraint member field has already been filled in appropriately, since the LBJava compiler will generate a class extending Foo whose constructor does so.
    
    Throws:
    
    Exception
  - valueOf
```
public abstract String valueOf(Learner c,
                               Object o)
                        throws Exception
```
    Retrieves the value of the specified variable as identified by the classifier and the object that produce that variable.
    
    Parameters:
    
    c - The classifier producing the variable.
    
    o - The object from which the variable is produced.
    
    Returns:
    
    The current value of the requested variable.
    
    Throws:
    
    Exception
  - getNormalizer
```
public Normalizer getNormalizer(Learner c)
```
    Returns the normalization function associated with the given classifier in this inference. Derived classes that implement an inference algorithm for use in an LBJava source file are required to call this method to normalize the scores produced by classifiers before making use of those scores. By default, this method returns the IdentityNormalizer.
    
    Parameters:
    
    c - The classifier.
    
    Returns:
    
    The normalization function associated with the classifier.
  - getHeadType
```
public String getHeadType()
```
    Returns the fully qualified name of the type of the head object for this inference. By default, this method returns "java.lang.Object". It should be overridden by derived classes.
  - getHeadFinderTypes
```
public String[] getHeadFinderTypes()
```
    Returns the fully qualified names of the types of objects for which head finder methods have been defined. This method must be overridden by derived classes, since by default it returns a 0-length array and every Inference is required to have at least one head finder. Inference classes written by the compiler automatically override this method appropriately.
  - satisfied
```
public boolean satisfied()
```
    Determines if the constraints are satisfied by the current variable assignments.
  - getVariable
```
public PropositionalVariable getVariable(PropositionalVariable v)
```
    Retrieves the requested variable, creating it first if it doesn't yet exist.
    
    Parameters:
    
    v - A variable containing the same classifier, object, and prediction value as the desired variable.
    
    Returns:
    
    The Boolean variable corresponding to the event classifier(object) == prediction.
  - getVariable
```
public FirstOrderVariable getVariable(FirstOrderVariable v)
```
    Retrieves the requested variable, creating it first if it doesn't yet exist.
    
    Parameters:
    
    v - A variable containing the same classifier and object as the desired variable.
    
    Returns:
    
    The variable corresponding to the application of the classifier on the object.
  - visitAll
```
public void visitAll(Constraint c)
```
    The default method for visiting a constraint simply visits that constraint's children.
  - visit
```
public void visit(FirstOrderDoubleImplication c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(FirstOrderImplication c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(FirstOrderConjunction c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(FirstOrderDisjunction c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(FirstOrderEqualityTwoValues c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(FirstOrderEqualityWithValue c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(FirstOrderEqualityWithVariable c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(FirstOrderNegation c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(FirstOrderConstant c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(UniversalQuantifier c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(ExistentialQuantifier c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(AtLeastQuantifier c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(AtMostQuantifier c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(QuantifiedConstraintInvocation c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(PropositionalDoubleImplication c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(PropositionalImplication c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(PropositionalConjunction c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(PropositionalDisjunction c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(PropositionalAtLeast c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(PropositionalConstant c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(PropositionalNegation c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.
  - visit
```
public void visit(PropositionalVariable c)
```
    Derived classes override this method to do some type of processing on constraints of the parameter's type.
    
    Parameters:
    
    c - The constraint to process.

Class Inference

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

variables

constraint

head

Constructor Detail

Inference

Inference

Method Detail

exampleToString

getHead

infer

valueOf

getNormalizer

getHeadType

getHeadFinderTypes

satisfied

getVariable

getVariable

visitAll

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit

visit