org.lsmp.djep.matrixJep.function

Class MIf

java.lang.Object

org.nfunk.jep.function.PostfixMathCommand

org.lsmp.djep.matrixJep.function.MIf

All Implemented Interfaces:

MatrixSpecialEvaluationI, NaryOperatorI, PostfixMathCommandI

public class MIf
extends PostfixMathCommand
implements NaryOperatorI, MatrixSpecialEvaluationI

The if(condExpr,posExpr,negExpr) function. The value of trueExpr will be returned if condExpr is >0 (true) and value of negExpr will be returned if condExpr is <= 0 (false).

This function performs lazy evaluation so that only posExpr or negExpr will be evaluated. For Complex numbers only the real part is used.

An alternate form if(condExpr,posExpr,negExpr,zeroExpr) is also available. Note most computations are carried out over floating point doubles so testing for zero can be dangerous.

This function implements the SpecialEvaluationI interface so that it handles setting the value of a variable.

Author:

Rich Morris Created on 18-Nov-2003

Field Summary

Fields inherited from class org.nfunk.jep.function.PostfixMathCommand

curNumberOfParameters, numberOfParameters

Constructor Summary

Constructors

Constructor and Description
MIf()

Method Summary

Modifier and Type	Method and Description
Dimensions	calcDim(Dimensions[] dims) Find the dimension of this node.
MatrixValueI	calcValue(MatrixValueI res, MatrixValueI[] inputs) This method should not be called.
boolean	checkNumberOfParameters(int n) Checks the number of parameters of the function.
MatrixValueI	evaluate(MatrixNodeI node, MatrixEvaluator visitor, MatrixJep j) Evaluate the node, uses lazy evaluation.

Methods inherited from class org.nfunk.jep.function.PostfixMathCommand

checkStack, getNumberOfParameters, run, setCurNumberOfParameters

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.nfunk.jep.function.PostfixMathCommandI

getNumberOfParameters, run, setCurNumberOfParameters

Constructor Detail

MIf

public MIf()

Method Detail

calcDim

public Dimensions calcDim(Dimensions[] dims)
                   throws ParseException

Find the dimension of this node.

Specified by:

calcDim in interface NaryOperatorI

Throws:

ParseException

calcValue

public MatrixValueI calcValue(MatrixValueI res,
                              MatrixValueI[] inputs)
                       throws ParseException

This method should not be called. Use evaluate(org.lsmp.djep.matrixJep.nodeTypes.MatrixNodeI, org.lsmp.djep.matrixJep.MatrixEvaluator, org.lsmp.djep.matrixJep.MatrixJep) instead.

Specified by:

calcValue in interface NaryOperatorI

Throws:

ParseException

evaluate

public MatrixValueI evaluate(MatrixNodeI node,
                             MatrixEvaluator visitor,
                             MatrixJep j)
                      throws ParseException

Evaluate the node, uses lazy evaluation.

Specified by:

evaluate in interface MatrixSpecialEvaluationI

Parameters:

node - The top node.

visitor - The parser visitor

j - The current MatrixJep instance.

Returns:

Value after evaluation.

Throws:

ParseException

checkNumberOfParameters

public boolean checkNumberOfParameters(int n)

Description copied from class: PostfixMathCommand

Checks the number of parameters of the function. Functions which set numberOfParameter=-1 should overload this method

Specified by:

checkNumberOfParameters in interface PostfixMathCommandI

Overrides:

checkNumberOfParameters in class PostfixMathCommand

Parameters:

n - number of parameters function will be called with.

Returns:

False if an illegal number of parameters is supplied, true otherwise.