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A powerful function parser

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4.40/5 (21 votes)
22 Feb 2000 140.7K   2.2K   60   23
A simple yet powerful function parser that parses and evaluates standard mathematical functions
  • Download source files - 82 Kb
  • The inspiration to write this code was to have an easy-to-use parser for functions given as string. You have a string like "cos(x)-7*x/(1+x)", and you want to compute some values, maybe for displaying the graph of the function. You can write code like this:

    CFunction<long double>* fkt = CFunction<long double>::Parse("cos(x)-7*x/(1+x)");
    long double y = fkt->Execute(1.5);

    There are lots of definitions in the background, but the result is easy and fast! There is a one-time pasing step to construct the function tree, and function evaluations are only calls of standard math functions like sin, +, *, sqrt. When you want to know details about the implementaion, you should look into the source code. It would be too complex to describe the parsing algorithm here.

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    Comments and Discussions

     
    GeneralTo B.Starks, W.Dean, & J.Andreas Pin
    Amit Gefen8-Nov-01 12:43
    Amit Gefen8-Nov-01 12:43 
    GeneralOperators/precedence/types etc Pin
    Andrew Phillips26-Sep-01 18:04
    Andrew Phillips26-Sep-01 18:04 
    GeneralVery good success with this Pin
    Jeff12-May-01 8:59
    Jeff12-May-01 8:59 
    GeneralYou must read jeff's reply..!! then you will success Pin
    JsSong25-Mar-02 14:47
    JsSong25-Mar-02 14:47 
    GeneralBugs etc below should be renamed to Dean Wyant knows little about programming. Pin
    13-Apr-01 7:36
    suss13-Apr-01 7:36 
    GeneralRe: Bugs etc below should be renamed to Dean Wyant knows little about programming. Pin
    Dean Wyant30-Apr-04 10:11
    Dean Wyant30-Apr-04 10:11 
    GeneralA good Parser Pin
    18-Jan-01 17:57
    suss18-Jan-01 17:57 
    GeneralRe: A good Parser Pin
    Ping He9-May-01 23:36
    Ping He9-May-01 23:36 
    GeneralRe: A good Parser Pin
    MathePeter3-Jul-07 3:22
    MathePeter3-Jul-07 3:22 
    GeneralDoes not understand decimals Pin
    Anonymous3-Nov-00 4:55
    Anonymous3-Nov-00 4:55 
    QuestionBugs etc. - How does it deserve such high ratings? Pin
    Dean Wyant23-May-00 13:59
    Dean Wyant23-May-00 13:59 
    QuestionEnglish translation of comments? Pin
    Peter Helmers10-Apr-00 4:03
    sussPeter Helmers10-Apr-00 4:03 
    GeneralFunctionParser Pin
    Armin Zürcher12-Mar-00 1:57
    sussArmin Zürcher12-Mar-00 1:57 

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