question: public static String format ( double [ ] v , int w , int d ) { DecimalFormat format = new DecimalFormat ( ) ; format . setDecimalFormatSymbols ( new DecimalFormatSymbols ( Locale . US ) ) ; format . setMinimumIntegerDigits ( 1 ) ; format . setMaximumFractionDigits ( d ) ; format . setMinimumFractionDigits ( d ) ; format . setGroupingUsed ( false ) ; int width = w + 1 ; StringBuilder msg = new StringBuilder ( ) ; msg . append ( '\n' ) ; for ( int i = 0 ; i < v . length ; i ++ ) { String s = format . format ( v [ i ] ) ; int padding = Math . max ( 1 , width - s . length ( ) ) ; for ( int k = 0 ; k < padding ; k ++ ) { msg . append ( ' ' ) ; } msg . append ( s ) ; } return msg . toString ( ) ; }
target:  Returns a string representation of this vector.