Mathematic Expression Solutions of C/C++

Focus more on C Language. 

Problem: 

If I would like to read a file (math.txt) which stores several formula, like

• f(a,x)=ax^2+bx
• f(a,b,x)=a*cos(b*x)+b*sin(a*x)
  

Inputs: data pair

• x and y
  

Goal: for all x, y

• f(a,x)=y
• f(a,b,x)=y
  

So I need a Parser to help me read the math.txt to evaluate the functions.

Freeware

• CodeProject - An extensible math expression parser with plug-ins - C++/VB6/C#
• Souceforge-muParser - DLL:VC++/GCC++
• uCalc Fast Math Parser- Borland C++ Builder, Delphi, PowerBASIC (PB/DLL and PB/CC), Visual Basic (classic), .NET (C#, VB.NET etc), and Visual C++.
  

Royalty free

• Bestcode your software resource - C++/Delphi/VB/VC++/.NetC#
  
• USPExpress - COM:Visual C#, Visual Basic, Visual C++, Delphi or Fortran.

Also, I search some libraries for advanced mathematics calculation

Freeware

• Mathtools - C/C++/Matlab/Java/Fortran/VB
• ALGLIB -C/C++/Delphi/Vb6/Zonnon
• Free Numerical Libraries, Mathematical Libraries, Statistical Libraries
  

Royalty free

• SciMath C/C++ Scientific Math Library - C/C++
  

License

• Solving Engineering Problems Using MATLAB C++ Math Library