The C++ Mathematical Expression Library (ExprTk) is a simple to use, easy to integrate and extremely efficient and fast mathematical expression parsing and evaluation engine. The parsing engine supports various kinds of functional, logic processing semantics and is very easily extendible.
http://www.partow.net/programming/exprtk/index.html
Mathematical operators (+, , *, /, %, ^)
Functions (min, max, avg, sum, abs, ceil, floor, round, roundn, exp, log, log10, logn, root, sqrt, clamp, range)
Trigonometry (sin, cos, tan, acos, asin, atan, atan2, cosh, cot, csc, sec, sinh, tanh, d2r, r2d, d2g, g2d, hyp)
Equalities, Inequalities and Assigment (=, ==, , !!=, , >=, :=,
30 Day SummaryOct 25 2015 — Nov 24 2015

12 Month SummaryNov 24 2014 — Nov 24 2015
