Package edu.hws.jcm.functions
Class SummationParser
java.lang.Object
edu.hws.jcm.functions.SummationParser
- All Implemented Interfaces:
MathObject
,ParserExtension
,Serializable
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:
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
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.getName()
Get the name, which will be used in place of "sum" in expressions.void
Set the name, which will be used in place of "sum" in expressions.
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Constructor Details
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SummationParser
public SummationParser()
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Method Details
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setName
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 interfaceMathObject
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getName
Get the name, which will be used in place of "sum" in expressions.- Specified by:
getName
in interfaceMathObject
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doParse
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 (,invalid input: '<'lower-limit>,invalid input: '<'upper-limit>, ). This method is not meant to be called directly - Specified by:
doParse
in interfaceParserExtension
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