Units is a program for computations on values expressed in terms of different measurement units.
Using this program you can find out, for example, that 6 ft 4 in is about 1.93 m, that temperature of 75 degrees Fahrenheit is about 24 degrees Celsius, that 8 liters per 100 km is about the same as 29 miles per gallon, that electric current of 5 mA corresponds to the flow of about 3.12e16 electrons per second, or that the energy of a photon of yellow sodium light with wavelength 5896 Å is 2.103 eV.
The program supports complicated expressions and a number of mathematical functions, as well as user-defined linear, nonlinear, and piecewise-linear functions. All knowledge about measurement units is contained in a separate file 'units.dat'. In addition to many units from different domains and periods, the file contains a number of physical and other constants (such as pi, speed of light, mass of Earth), as well as extensive comments that can be retrieved with the help of the Units program. You can add your own definitions in separate file(s).
Units is written in Java, which means you can use it directly under any operating system that supports Java Runtime Environment release 1.5.0 or later. You can embed it as an applet in a Web page.
If you do not want to use Units as an applet, you have to download the Java archive (JAR) file that contains the executable Java classes.
Save the JAR file in any directory, under any name of your choice, with extension '.jar'. You invoke it by double-clicking on the JAR icon. If this does not work, you can type
java -jar jarfileat the command prompt, where jarfile is the name you gave to the JAR file. Each way should open the graphic interface of Units. If you want instead an interactive version, type
java -jar jarfile -iat the command prompt. Refer to user's manual for other forms of invocation.
The complete package containing the JAR and the Java source can be downloaded as a gzipped tar file from the SourceForge project page.
The program is a Java version of GNU Units 1.88, extended with a graphic user interface. The original GNU Units was written in C by Adrian Mariano (adrian@cam.cornell.edu). The file 'units.dat' defining the units was created by Adrian Mariano, and is maintained by him. This package contains the latest version obtained from the GNU Units directory.
GNU Units copyright © 1996, 1997, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2010 by Free Software Foundation, Inc. Java version copyright © 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 by Roman R Redziejowski (roman.redz@tele2.se).
This program is free software: you can redistribute it and/or modify
it under the terms of the
GNU Library General Public License
as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
The program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
The program has only been tested under Windows XP using Firefox, Netscape Navigator and Internet Explorer.
Latest change 2010-11-01