std
Computes the inverse cumulative distribution function for a standard normal distribution see, W. J. Cody, Rational Chebyshev approximations for the error function Math. Comp. pp 631-638 this is without the extra refinement and has relative error of 1.15e-9 http://www.math.uio.no/~jacklam/notes/invnorm/
Return
the "z" value associated with the p
Parameters
p
the probability to be evaluated, p must be within 0,1 p = 0.0 returns Double.NEGATIVE_INFINTITY p = 1.0 returns Double.POSITIVE_INFINITY