# A Powerful Function Parser

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**Andreas Jdger**on**March 1st, 2000**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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