How can an application execute a mathematical formula edited in an Edit

[nunca]

Hello every one
I am so tired about this problem. Please can someone help me.
In my application I need perform a procedure which can read a mathematical formula form an Edit and execute it. The problem is how can I convert this string to a real function
Thank you

[D_Drmmr]

In my application I need perform a procedure which can read a mathematical formula form an Edit and execute it. The problem is how can I convert this string to a real function

You cannot convert it to a C++ function, because those only exist at compile time, not in run-time.
What you can do is implement a parser that can interpret the formula and either calculate the result directly or produce a bunch of objects that can calculate the result. Read up on recursive descent parsers to learn more. You could also try to use a library such as Boost Spirit to build the parser.

[MikeAThon]

For parsing a string in an attempt to interpret it as a function, the following article might give you some ideas: "Symbolic Differentiation" By Hatem Mostafa at http://www.codeproject.com/Articles/...ifferentiation

It's not easy to do.

Mike

[Mike Pliam]

Check this out.

http://www.codeproject.com/Articles/...essions-Parser

I've used it and it is quite useful for the purpose that you have stated.

[MikeAThon]

@Mike, nice find.

@OP, here is another one at that site: "An extensible math expression parser with plug-ins" by Mathieu Jacques at http://www.codeproject.com/Articles/...-with-plug-ins