Gnuplot is aportablecommand-linedriven graphingutility forLinux, OS/2, MSWindows, OSX,VMS, and manyotherplatforms. Thesource code iscopyrighted butfreelydistributed(i.e., youdon't haveto pay for it).It wasoriginallycreated toallowscientists andstudents tovisualizemathematicalfunctions anddatainteractively,but has grownto support manynon-interactiveuses such asweb scripting.It is also usedas a plottingengine bythird-partyapplicationslike Octave.Gnuplot has b
The C++MathematicalExpressionToolkit Library(ExprTk) is asimple to use,easy tointegrate andextremelyefficientrun-timemathematicalexpressionparser andevaluationengine. ExprTksupportsnumerous formsof functional,logical andvectorprocessingsemantics andis very easilyextendible.