calculate

This function calculates a mathmatic formula. It is somewhat like a calculator, but without an usable frontend. Often you have the problem, that you just want write down the complete formular, but on GUI-based calculators you can't, here you can! Allowed are the usual operators (+, -, *, /, %) and the following functions:

• exp($arg) (exp(1) = 2,718...)
• log($arg, $basis) (log(2, 8) = 1/3)
• pow($basis, $exponent) (pow(4, 2) = 16)
• sqrt($arg) (sqrt(16) = 4)

Attention: The comma (,) is reserved to devide the parameters of function. The comma in this way is represented by the dot (.).