Measurements for OpenOffice.org

"Measurements" is an Openoffice.org Calc add-in I wrote that provides a basic set of spreadsheet functions for manipulating scientific measurements, tracking units of measure and significant figures.  It is available here and on the main OpenOffice.org Extensions site.

To install: The add-in comes in a UNO package named measurements-V.oxt, where V stands for the version.  Download the newest version.  In OpenOffice, go to Tools -> Extension Manager... -> My Extensions -> Add... -> browse for measurements-V.oxt -> Open.  Then restart OpenOffice.org.  (If you are upgrading, remove the old package and restart OpenOffice.org first.)

Here is the UNO package for download.

To use:

• You might like to look at the demo spreadsheet.
• Input a measurement as a string consisting of a floating-point numerical value (scientific notation preferred), a space, and a unit expression.  The unit expression consists of one or more unit symbols, each optionally raised to an integer power with ^, and separated by *, space (implied multiply), or / (inverts the rest of the expression).  Example: 1.20E3 kg*m^2/s^2.  Only a few units are supported so far; see the list in Unit.java.
• The number of significant figures is inferred from your entry.  You can indicate that a number is exact by following it with a lowercase x.
• A measurement that does not contain a space is interpreted as an exact pure number (because the spreadsheet forgets the number of sig figs entered by the user anyway).  To enter an inexact pure number, enter a formula containing a literal string with a trailing space: ="1.497 ".
• Use the M* functions (MADD, MSUB, MMUL, MDIV, MNEG, MPOWINT, MROOTINT, MPOW, MEXP, MLN) to do arithmetic on measurements.  A computed result shows up as a scientific-notation value to the correct number of significant figures and units (for your benefit) followed by a code containing the add-in's representation of the result (including precision beyond the significant figures).  Example: If mass is in A1 and volume is in A2, put this in A3 to compute the density: =MDIV(A1;A2).
• The difference between MPOWINT and MPOW is that MPOW lets you use a pure-number measurement for the exponent but requires the base to be a pure number, while MPOWINT lets you use a base with units but requires the exponent to be an integer.
• To have a computed result shown in units other than the default, pass it and the desired unit expression to MSTRAS.  Example: =MSTRAS("1 m^3";"L").  This affects only the user-friendly form, not the code.
• If you're picky and want to show the user-friendly form of a result without the code, use MCLEANSTR.  There is also MCLEANSTRAS.
• If you see ERROR, something went wrong, but you have to guess what.  :)  A future version might have better diagnostics.

Legal

Measurements consists of:

• Robert Harder's Base 64 encoder/decoder, which he has placed in the public domain
• Code by me, Matt McCutchen, which I hereby place in the public domain

Measurements comes with absolutely no warranty.

Version log

• Version 1 (2007-09-09): It works!
• Version 1.1 (2008-01-07): Packaging adjusted so it installs properly in OpenOffice.org 2.3.
• Version 1.2 (2009-02-06): Update build process for OpenOffice.org 3.0 and improve documentation.
• Version 1.3 (2009-09-15): Adjust packaging and build against Java 1.5 for greater compatibility.

Source repository

Here is the git repository containing the source code.  You can follow the link to browse the repository in gitweb or clone from it using the git tools.