question: public static double ulp ( double d ) { if ( Double . isNaN ( d ) ) { return Double . NaN ; } if ( Double . isInfinite ( d ) ) { return Double . POSITIVE_INFINITY ; } if ( d == 0.0 ) { return Double . MIN_VALUE ; } d = Math . abs ( d ) ; if ( d == Double . MAX_VALUE ) { return MAX_ULP ; } return nextAfter ( d , Double . MAX_VALUE ) - d ; }
target:  Returns the size of an ulp (units in the last place) of the argument.