net.sourceforge.webcompmath.functions
Class SummationParser

java.lang.Object
  net.sourceforge.webcompmath.functions.SummationParser

All Implemented Interfaces:

java.io.Serializable, MathObject, ParserExtension

public class SummationParser
extends java.lang.Object
implements ParserExtension

The SummationParser class makes it possible to use summations such as sum(i,1,5,x^i) in a Parser. The summation psedu-function has four parameters: (1) The summation variable, which must be an identifier; (2) The lower limit for the summation, given as an expression; (3) The upper limit for the summation, given as an expression; and (4) The expression that is summed. The values of the lower and upper limit expressions are rounded to the nearest integer. The expression in the fourth parameter can (and presumably will) use the summation variable (as well as other identifiers known to the parser).

To use summations with a Parser p, just say p.add(new SummationParser()). It's unlikely that you will ever need to do anything else with SummationParsers. If you want to use a name other than "sum", you can change the name after creating the SummationParser object but before adding it to a parser. (Note, by the way, that parsers by default do not do factorials. If you want a parser that recognizes factorials, you could do something like p = new Parser(Parser.DEFAULT_OPTIONS | Parser.FACTORIAL).)

See Also:

Serialized Form

Constructor Summary

SummationParser()

Method Summary

void	doParse(Parser parser, ParserContext context) When the name of this ParserExtension is encountered by a parser with which the extension is registered, the parser calls this routine to parse the summation subexpression.
java.lang.String	getName() Get the name, which will be used in place of "sum" in expressions.
void	setName(java.lang.String name) Set the name, which will be used in place of "sum" in expressions.

Methods inherited from class java.lang.Object

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

Constructor Detail

SummationParser

public SummationParser()

Method Detail

setName

public void setName(java.lang.String name)

Set the name, which will be used in place of "sum" in expressions. This should not be done after the SummationParser has been added to a Parser. The default name is "sum".

Specified by:

setName in interface MathObject

Parameters:

name - name of summation

getName

public java.lang.String getName()

Get the name, which will be used in place of "sum" in expressions.

Specified by:

getName in interface MathObject

Returns:

name of summation

doParse

public void doParse(Parser parser,
                    ParserContext context)

When the name of this ParserExtension is encountered by a parser with which the extension is registered, the parser calls this routine to parse the summation subexpression. The subexpression has the form ( , , , ). This method is not meant to be called directly

Specified by:

doParse in interface ParserExtension

Parameters:

parser - parser to use

context - context to use