Code base on (stolen from):
 + Jonas Raoni Soares Silva
 @ http://jsfromhell.com/classes/math-processor [rev. #1]

operators
    + add
    - subtract
    % modulo
    / divide
    * multiply
    ^ power
    > greater than
    < less then
    = equal to
    ~ not equal to

functions:
    div(a, b)
    round(a, b)
    if(a, b, c)
    fra(a)
    min(n1, n2, n3 ...)
    max(n1, n2, n3 ...)
    sum(n1, n2, n3 ...)
    average(n1, n2, n3 ...)
    wma(n1, n2, n3 ...)
    ema(a)
    isnan(a)
    isfinite(a)
    number(a)

identifiers:
    infinity
    nan
    true
    false

alert(new MathProcessor().parse('10 + 1'))
alert(new MathProcessor().parse('10 + 3 * 5 - 1'))
alert(new MathProcessor().parse('(10 + 3) * 5 - 1'))
alert(new MathProcessor().parse('3.1415/2'))
alert(new MathProcessor().parse('min(1,2,3,4)'))
alert(new MathProcessor().parse('max(1,2*2,3,4*7)'))
alert(new MathProcessor().parse('max(1,2,3,4)'))
alert(new MathProcessor().parse('fra(73.2)'))