question: public static double quantile ( double x , double mu , double sigma , double skew ) { x = NormalDistribution . standardNormalQuantile ( x ) ; if ( Math . abs ( skew ) > 0. ) { x = ( 1. - Math . exp ( - skew * x ) ) / skew ; } return mu + sigma * x ; }
target:  Inverse cumulative probability density function (probit) of a normal distribution.