public static double meanTruncLower ( double mu , double sigma , double lowerBound ) { double alpha = ( lowerBound - mu ) / sigma ; double phiAlpha = densityNonTrunc ( alpha , 0 , 1.0 ) ; double cPhiAlpha = cumulativeNonTrunc ( alpha , 0 , 1.0 ) ; return mu + sigma * phiAlpha / ( 1.0 - cPhiAlpha ) ; }
Returns the mean of the normal distribution truncated to 0 for values of x < lowerBound