question: public static double [ ] [ ] randn ( int rows , int cols , Random r ) { double X [ ] [ ] = new double [ rows ] [ cols ] ; for ( int i = 0 ; i < rows ; i ++ ) { for ( int j = 0 ; j < cols ; j ++ ) { X [ i ] [ j ] = r . nextGaussian ( ) ; } } return X ; }
target:  A 2D array of Gaussian random numbers 