junitconv
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Summary	Universal Units of Measure Converter built as a Java Applet
Categories	None
License	GNU General Public License (GPL v. 2.0)
Owner(s)	nicolaasuni

Name	JUnitConv
Version	1.0.003
Date	2006-10-18
Author	Nicola Asuni
Copyright	Tecnick.com S.r.l. Via Ugo Foscolo n.19 09045 Quartu Sant'Elena (CA) ITALY www.tecnick.com
License	GNU LESSER GENERAL PUBLIC LICENSE v.2.1

Source Code and Documentation

• Browse Documentation
• Browse CVS
• Download JUnitConv from SourceForge

Description

JUnitConv is an universal Units of Measure Converter, it converts numbers from one unit of measure to another.
Built as a Java Applet, JUnitConv is platform-independent and highly-configurable, it supports an unlimited number of Units Categories, Units of Measure and Multiplier Prefixes that could be customized using external text files. You could setup your own data files using your preferred spoken language, units categories, units definitions and multiplier prefixes. The default configuration data files contains 580 basic units of measure definitions divided in 31 categories and 27 multiplier prefixes for a total of 15660 composed units.

Main Features

• browser-independent, works fine with any browser that support at least Java 1.1
• 580 basic units of measure definitions divided in 31 categories and 27 multiplier prefixes
• customizables units, categories, multipliers and labels using external text files
• supports units descriptions, used to display units definitions and history (if available)
• supports multiplier prefixes
• supports basic formulas as units conversion parameters
• supports result precision (max number of decimal places)
• customizables charset encoding, supports international character sets (require appropriate OS/browsers)
• customizables background and foreground colors
• customizables font type, style and size

Note: the conversion accuracy is influenced by a couple of factors such as client machine precision and units data definitions.

Example

Setup

To display the JUnitConv, copy the .jar file on your site and add the applet tag to your XHTML/HTML document. To customize quickly the applet, I suggest to cut and paste the applet tag code used in the online example and modify it to fit your needs.

The following tables illustrates the meaning and function of each parameter.

Applet Attributes (<applet attribute_name="attribute_value" ... >)

name values default required codebase relative path to applet archive directory (e.g.: "../java/")   yes archive junitconv.jar (name of applet archive)   yes code com.tecnick.junitconv.JUnitConv.class (name of main class)   yes width applet width in pixels   yes height applet height in pixels   yes hspace applet horizontal space   no vspace applet vertical space   no align applet alignment left right top middle bottom   no name applet name   no id applet id   no alt applet alternate text content   no

The following are the main applet parameters.

Main Parameters (<param name="param_name" value="param_value" />)

name values default required background_color applet background color - the color format is a set of three hexadecimal numbers (from 00 to FF) representing primary colors RRGGBB (R=Red, G=Green, B=Blue) CCCCCC no foreground_color applet foreground color (text color) - the color format is a set of three hexadecimal numbers (from 00 to FF) representing primary colors RRGGBB (R=Red, G=Green, B=Blue) 000000 no font font name Helvetica, Verdana, Arial no font_style font style PLAIN BOLD ITALIC BOLD+ITALIC PLAIN no font_size font height in pixels 11 no page_encoding encoding character set of the html page where the applet is loaded iso-8859-1 no encoding encoding character set for the applet iso-8859-1 no labels_data_file relative path to text file containing the applet labels (fields names) eng/labels.txt yes multiplier_data_file relative path to text file containing the multipliers definitions eng/muldata.txt yes categories_data_file relative path to text file containing the units categories eng/catdata.txt yes units_data_file relative path to text file containing the units definitions eng/unitdata.txt yes

Customize Units

Conversion Formula

All conversions are performed using the following formula:

OV = ( ( IV · IS · IM^IP ) + IO - OO ) / ( OS · OM^OP)

where:

• IV = Input Value
• IS = Input Conversion Factor
• IM = Input Multiplier Value
• IP = Input Multiplier Exponent
• IO = Input Conversion Offset
• OV = Output Value
• OS = Output Conversion Factor
• OM = Output Multiplier Value
• OP = Output Multiplier Exponent
• OO = Output Conversion Offset

Data Files

Labels, Categories, Units and Multipliers are specified on external text files (data files). These data files can be changed manually using a simple text editor or using a spreadsheet editor such as Microsoft Excel (open and save files using the Tab delimited Text format).

Tab delimited Text means that each file row identify one element (one category, one unit, one multiplier or one label). Each row terminate with newline character '\n' (rows separator). The data values of each single element are separated by tabulation character '\t' (columns separator), even if not present.

labels_data_file

On this file each row represent one JUnitConv label (field name).

multiplier_data_file

This file contains the Multiplier Prefixes definitions (e.g.: k = kilo = 10³ = 1000)
The columns fields are:

• symbol
• name
• value (IM or OM on formula)

categories_data_file

This file contains the Units Categories Names.
The row number of each category represent the CATEGORY_ID index.

units_data_file

This file contains the Units of Measure definitions.
The columns fields are:

• CATEGORY_ID (see the previous categories_data_file description)
• symbol
• name
• conversion factor (IS or OS on formula), the reference unit has value 1
• offset (IO or OO on formula), it's used to convert between temperatures scales, normally it's zero
• unit multiplier exponent (IP or OP on formula), for example this has value 1 on meters, 2 on m² and 3 on m³
• description

Numeric Fields

On data files, each numeric field support scientific notation (e.g.: 3.7E-2 = 3.7 · 10^-2 = 0.037) but can be also specified using basic formulas and constants.

On formulas the following symbols are used (in order of precedence):

• P = Pi = 3.14159...
• X = e = 2.71828...
• * = multiplication
• / = division
• + = sum
• - = difference
• ^ = power elevation

Note that parenthesis are not supported, so please check twice the operators precedence.

Examples:

• P/180^2 = (Pi/180)² = 3.046174...
• 1+3.7E-2 = 1 + (3.7 · 10^-2) = 1.037
• 5^3-1 = 5^3-1 = 5² = 25
• 72*4.55/25.4 = (72 · 4.55) / 25.4 = 12.8976...

References

The following documents, books and software applications has been used as reference to build the default units data file (unitdata.txt).

• The Jargon Dictionary
• NIST Definitions of the SI base units
• NIST Handbook 44,Appendix C
• MegaConverter2
• Celsius, Fahrenheit, Kelvin, Réaumur,and Rankine Temperature Conversion
• Unit Conversion Table
• Angle Conversion Factors
• Mils Versus Mils Versus Mils By Joe Huffman
• Measures from Antiquity and the Bible
• G. Biondo, E. Sacchi - Manuale di Elettronica e telecomunicazioni - HOEPLI

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