se.lth.control

Class DoubleFormat

java.lang.Object

se.lth.control.DoubleFormat

public class DoubleFormat
extends java.lang.Object

DoubleFormat is a class for formatting numbers of type Double. The format is specified using two numbers: maxPositions, which is the maximum number of characters in the formatted output, and numDigits, which is the desired number of significant digits in the formatted output. The output may contain both fewer and more significant digits than numDigits, but maxPositions will always be honored. Some examples:

(maxPositions,numDigits)	(6,3)	(8,4)	(11,5)
1.23456E-123	0.###	1.E-123	1.234E-123
1.23456E-6	1.E-3	1.23E-6	1.2346E-3
0.123456	0.123	0.1234	0.12346
123.456	123.	123.4	123.46
12345.6	1.E+4	12346.	12346.
1.23456E+8	#####	1.23E+6	1.2346E+6

As can be seen from the examples, if maxPositions is small and the number to be formatted is very large or very small, then there is no way to show the number and keep the significance. In that case a sequence of hash marks (#) is shown instead. This can only occur if maxPositions < 8.

Constructor Summary

Constructors

Constructor and Description
DoubleFormat(int maxPositions, int numDigits) Create a DoubleFormat.

Method Summary

Modifier and Type	Method and Description
java.lang.String	format(double num) Formats num.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DoubleFormat

public DoubleFormat(int maxPositions,
                    int numDigits)

Create a DoubleFormat.

Parameters:

maxPositions - The maximum number of positions for the output string. Minimum value: numDigits + 2.

numDigits - The desired number of significant digits. Minimum value: 2.

Throws:

java.lang.IllegalArgumentException - if any of the parameter values are too small

Method Detail

format

public java.lang.String format(double num)

Formats num.