org.lsmp.djep.djep

Class DJep

java.lang.Object

org.nfunk.jep.JEP

org.lsmp.djep.xjep.XJep

org.lsmp.djep.djep.DJep

Direct Known Subclasses:

MatrixJep

public class DJep
extends XJep

Adds differentation facilities to JEP. For example

 DJep j = new DJep();
 j.addStandardDiffRules();
 ....
 Node node = j.parse("x^3");
 Node diff = j.differentiate(node,"x");
 Node simp = j.simplify(diff);
 j.println(simp);
 Node node2 = j.parse("diff(x^4,x)");
 Node proc = j.preprocess(node2);
 Node simp2 = j.simplify(proc);
 j.println(simp2);
 

Author:

Rich Morris Created on 16-Nov-2003

Field Summary

Fields

Modifier and Type	Field and Description
protected DifferentiationVisitor	dv

Fields inherited from class org.lsmp.djep.xjep.XJep

commandv, copier, nf, pv, simpv, subv, tu

Fields inherited from class org.nfunk.jep.JEP

allowAssignment, allowUndeclared, errorList, ev, funTab, implicitMul, numberFactory, opSet, parser, symTab

Constructor Summary

Constructors

Modifier	Constructor and Description
	DJep() Standard constructor.
protected	DJep(DJep j)

Method Summary

Modifier and Type	Method and Description
void	addDiffRule(DiffRulesI rule) Adds a rule with instruction on how to differentiate a function.
boolean	addStandardDiffRules() Adds the standard set of differentation rules.
Node	differentiate(Node node, String name) Differentiate an equation with respect to a variable.
DifferentiationVisitor	getDifferentationVisitor() Returns the visitor used for differentiation.
XJep	newInstance() Creates a new instance of XJep with the same components as this one.
XJep	newInstance(SymbolTable st) Creates a new instance of XJep with the same components as this one and the specified symbol table.

Methods inherited from class org.lsmp.djep.xjep.XJep

addComplex, addStandardConstants, addStandardFunctions, calcVarValue, continueParsing, deepCopy, evaluate, getNodeFactory, getPrintVisitor, getTreeUtils, getVarsInEquation, preprocess, print, print, println, println, recursiveGetVarsInEquation, restartParser, restartParser, simplify, substitute, substitute, toString

Methods inherited from class org.nfunk.jep.JEP

addConstant, addFunction, addVariable, addVariable, addVariable, evaluate, getAllowAssignment, getAllowUndeclared, getComplexValue, getErrorInfo, getEvaluatorVisitor, getFunctionTable, getImplicitMul, getNumberFactory, getOperatorSet, getParser, getSymbolTable, getTopNode, getTraverse, getValue, getValueAsObject, getVar, getVarValue, hasError, initFunTab, initSymTab, parse, parseExpression, removeFunction, removeVariable, setAllowAssignment, setAllowUndeclared, setImplicitMul, setTraverse, setVarValue

Methods inherited from class java.lang.Object

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

Field Detail

dv

protected DifferentiationVisitor dv

Constructor Detail

DJep

public DJep()

Standard constructor. Use this instead of JEP or XJep if differentation facilities are required.

DJep

protected DJep(DJep j)

Method Detail

differentiate

public Node differentiate(Node node,
                          String name)
                   throws ParseException

Differentiate an equation with respect to a variable.

Parameters:

node - top node of the expression tree to differentiate.

name - differentiate with respect to this variable.

Returns:

the top node of a new parse tree representing the derivative.

Throws:

ParseException - if for some reason equation cannot be differentiated, usually if it has not been taught how to differentiate a particular function.

newInstance

public XJep newInstance()

Description copied from class: XJep

Creates a new instance of XJep with the same components as this one. Sub classes should overwrite this method to create objects of the correct type.

Overrides:

newInstance in class XJep

newInstance

public XJep newInstance(SymbolTable st)

Description copied from class: XJep

Creates a new instance of XJep with the same components as this one and the specified symbol table. Sub classes should overwrite this method to create objects of the correct type.

Overrides:

newInstance in class XJep

getDifferentationVisitor

public DifferentiationVisitor getDifferentationVisitor()

Returns the visitor used for differentiation. Allows more advanced functions.

addStandardDiffRules

public boolean addStandardDiffRules()

Adds the standard set of differentation rules. Corresponds to all standard functions in the JEP plus a few more.

 sin,cos,tan,asin,acos,atan,sinh,cosh,tanh,asinh,acosh,atanh
 sqrt,log,ln,abs,angle
 sum,im,re are handled separately.
 rand and mod currently un-handled
 
 Also adds rules for functions not in JEP function list:
        sec,cosec,cot,exp,pow,sgn 
 
 TODO include if, min, max, sgn
 

Returns:

false on error

addDiffRule

public void addDiffRule(DiffRulesI rule)

Adds a rule with instruction on how to differentiate a function.

Parameters:

rule -