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JEP is a Java library for parsing and evaluating mathematical expressions.
The newest version!
/* @author rich
* Created on 16-Nov-2003
*/
package org.lsmp.djep.xjep;
import org.nfunk.jep.*;
import org.nfunk.jep.function.Exp;
import org.nfunk.jep.function.PostfixMathCommandI;
import org.lsmp.djep.xjep.PrintVisitor.PrintRulesI;
import org.lsmp.djep.xjep.function.*;
import java.util.*;
import java.io.PrintStream;
import java.io.Reader;
/**
* An extended version of JEP adds various routines for working with trees.
* Has a NodeFactory, and OperatorSet, TreeUtils
* and Visitors DoNothingVisitor,
* @author Rich Morris
* Created on 16-Nov-2003
*/
public class XJep extends JEP {
/** Creates new nodes */
protected NodeFactory nf = null;
/** A few utility functions. */
protected TreeUtils tu = null;
protected DeepCopyVisitor copier = null;
protected SubstitutionVisitor subv = null;
protected SimplificationVisitor simpv = null;
protected CommandVisitor commandv = null;
protected PrintVisitor pv = null;
private VariableFactory vf = new XVariableFactory();
/**
* Create a new XJep will all the function of JEP plus printing and other features.
*/
public XJep()
{
this.symTab = new XSymbolTable(vf);
/* Creates new nodes */
nf = new NodeFactory(this);
/* Collects operators **/
opSet = new XOperatorSet();
/* A few utility functions. */
tu = new TreeUtils();
copier = new DeepCopyVisitor();
subv = new SubstitutionVisitor();
ev = new XEvaluatorVisitor();
simpv = new SimplificationVisitor();
commandv = new CommandVisitor();
pv = new PrintVisitor();
pv.addSpecialRule(opSet.getElement(),new PrintRulesI() {
public void append(Node node, PrintVisitor pv) throws ParseException {
node.jjtGetChild(0).jjtAccept(pv, null);
node.jjtGetChild(1).jjtAccept(pv, null);
}});
}
/** Copy constructions, reuses all the components of argument. */
protected XJep(XJep j)
{
super(j);
this.commandv=j.commandv;
this.copier=j.copier;
this.ev=j.ev;
this.nf=j.nf;
this.opSet=j.opSet;
this.pv=j.pv;
this.simpv=j.simpv;
this.subv=j.subv;
this.tu=j.tu;
}
private JEP ingrediant = null;
/** Conversion constructor.
* Turns a JEP object into an XJep object.
* @param j
*/
public XJep(JEP j)
{
ingrediant=j;
/* Creates new nodes */
nf = new NodeFactory(this);
this.symTab = new XSymbolTable(vf);
this.funTab = j.getFunctionTable();
/* Collects operators **/
opSet = new XOperatorSet(j.getOperatorSet());
/* A few utility functions. */
tu = new TreeUtils();
copier = new DeepCopyVisitor();
subv = new SubstitutionVisitor();
ev = new XEvaluatorVisitor();
simpv = new SimplificationVisitor();
commandv = new CommandVisitor();
pv = new PrintVisitor();
}
/**
* 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.
*/
public XJep newInstance()
{
XJep newJep = new XJep(this);
return newJep;
}
/**
* 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.
*/
public XJep newInstance(SymbolTable st)
{
XJep newJep = new XJep(this);
newJep.symTab = st;
return newJep;
}
public void addStandardFunctions()
{
if(ingrediant!=null)
{
ingrediant.addStandardFunctions();
}
else super.addStandardFunctions();
addFunction("eval",new Eval());
addFunction("Sum",new Sum(this));
addFunction("Product",new Product());
addFunction("Min",new Min());
addFunction("Max",new Max());
addFunction("MinArg",new MinArg());
addFunction("MaxArg",new MaxArg());
addFunction("Simpson",new Simpson());
addFunction("Trapezium",new Trapezium());
addFunction("toBase",new ToBase());
addFunction("toHex",new ToBase(16,"0x"));
addFunction("fromBase",new FromBase());
addFunction("fromHex",new FromBase(16,"0x"));
addFunction("exp",new Exp());
addFunction("Define",new Define(this));
try {
MacroFunction sec = new MacroFunction("sec",1,"1/cos(x)",this);
addFunction("sec",sec);
MacroFunction cosec = new MacroFunction("cosec",1,"1/sin(x)",this);
addFunction("cosec",cosec);
MacroFunction cot = new MacroFunction("cot",1,"1/tan(x)",this);
addFunction("cot",cot);
} catch (ParseException e) {System.err.println(e.getMessage());}
}
public void addStandardConstants()
{
if(ingrediant!=null)
{
ingrediant.addStandardConstants();
for(Enumeration en=ingrediant.getSymbolTable().elements();en.hasMoreElements();)
{
Variable var = (Variable) en.nextElement();
if(var.isConstant())
this.symTab.addConstant(var.getName(),var.getValue());
//else
// this.symTab.addVariable(var.getName(),var.getValue());
}
}
else super.addStandardConstants();
}
public void addComplex()
{
if(ingrediant!=null)
{
ingrediant.addComplex();
}
else super.addComplex();
try {
MacroFunction complex = new MacroFunction("macrocomplex",2,"x+i*y",this);
addFunction("macrocomplex",complex);
} catch (ParseException e) {System.err.println(e.getMessage());}
}
/** Returns a deep copy of an expression tree. */
public Node deepCopy(Node node) throws ParseException
{
return copier.deepCopy(node,this);
}
/** Returns a simplification of an expression tree. */
public Node simplify(Node node) throws ParseException
{
return simpv.simplify(node,this);
}
/** Pre-processes an equation to allow the diff and eval operators to be used. */
public Node preprocess(Node node) throws ParseException
{
return commandv.process(node,this);
}
/** Substitute all occurrences of a named variable with an expression tree. */
public Node substitute(Node orig,String name,Node replacement) throws ParseException
{
return subv.substitute(orig,name,replacement,this);
}
/** Substitute all occurrences of a set of named variable with a set of expression tree. */
public Node substitute(Node orig,String names[],Node replacements[]) throws ParseException
{
return subv.substitute(orig,names,replacements,this);
}
/** Prints the expression tree on standard output. */
public void print(Node node) { pv.print(node); }
/** Prints the expression tree on given stream. */
public void print(Node node,PrintStream out) { pv.print(node,out); }
/** Prints the expression tree on standard output with newline at end. */
public void println(Node node) { pv.println(node); }
/** Prints the expression tree on given stream with newline at end. */
public void println(Node node,PrintStream out) { pv.println(node,out); }
/** Returns a string representation of a expression tree. */
public String toString(Node node) { return pv.toString(node); }
/** Returns the node factory, used for constructing trees of Nodes. */
public NodeFactory getNodeFactory() {return nf;}
/** Returns the TreeUtilitities, used for examining properties of nodes. */
public TreeUtils getTreeUtils() { return tu; }
// public SimplificationVisitor getSimpV() { return simpv; }
/** Returns the PrintVisitor, used for printing equations. */
public PrintVisitor getPrintVisitor() { return pv; }
/**
* Calculates the value for the variables equation and returns that value.
* If the variable does not have an equation just return its value.
*/
public Object calcVarValue(String name) throws Exception
{
XVariable xvar = (XVariable) getVar(name);
return xvar.calcValue(this);
}
/**
* Continue parsing without re-initilising the stream.
* Allows re-entrance of parser so that strings like
* "x=1; y=2; z=3;" can be parsed.
* When a semi colon is encountered parsing finishes leaving the rest of the string unparsed.
* Parsing can be resumed from the current position by using this method.
* For example
*
* XJep j = new XJep();
* j.restartParser("x=1;y=2; z=3;");
* Node node;
* try {
* while((node = j.continueParsing())!=null) {
* j.println(node);
* } }catch(ParseException e) {}
*
* @return top node of equation parsed to date or null if empty equation
* @throws ParseException
* @see #restartParser(String)
*/
public Node continueParsing() throws ParseException {
return parser.continueParse();
}
/**
* Restarts the parser with the given string.
* @param str String containing a sequence of equations separated by semi-colons.
* @see #continueParsing
*/
public void restartParser(String str) {
parser.restart(new java.io.StringReader(str), this);
}
/**
* Restarts the parser with the given Reader.
* @param reader Reader from which equations separated by semi-colons will be read.
* @see #continueParsing
*/
public void restartParser(Reader reader) {
parser.restart(reader, this);
}
/**
* Finds all the variables in an equation.
*
* @param n the top node of the expression
* @param v a vector to store the list of variables (new variables will be added on end)
* @return v
*/
public Vector getVarsInEquation(Node n,Vector v) {
if(n instanceof ASTVarNode) {
Variable var = ((ASTVarNode) n).getVar();
if(!v.contains(var)) v.add(var);
}
else if(n instanceof ASTFunNode) {
for(int i=0;i
* For example if the equation is a+b and
* a=c+d, b=c+e then the
* result will be the sequence (c,d,a,e,b)
*
* @param n top node
* @param v vector for storing results, new variables will be added on the end.
* @return v, the ordered sequence of variables
* @throws ParseException if equation is recursive i.e. x=y; y=x+1;
*/
public Vector recursiveGetVarsInEquation(Node n,Vector v) throws ParseException {
if(n instanceof ASTVarNode) {
XVariable var = (XVariable) (((ASTVarNode) n).getVar());
if(!v.contains(var))
{
if(var.hasEquation())
recursiveGetVarsInEquation(var.getEquation(),v);
if(v.contains(var))
throw new ParseException("Recursive definition for "+var.getName());
v.add(var);
}
}
else if(n instanceof ASTFunNode) {
for(int i=0;i