Matt McCutchen's Web SiteMeasurements for LibreOffice  (Top, Design and status, Installation and usage, Legal, Version log, Source repository, Bottom).  Email me about this page.

Measurements for OpenOffice / LibreOffice

Status: minimally maintained; 2007-2009 (supersedes any conflicting remarks left on this page; see the home page for definitions)

"Measurements" is a proof-of-concept OpenOffice / LibreOffice Calc add-in I wrote that provides a basic set of spreadsheet functions for manipulating scientific measurements, tracking units of measure and uncertainty (input and displayed as significant figures, but tracked as an arbitrary floating-point number internally).

Measurements has pages on the OpenOffice extension site and the LibreOffice extensions site.

Design and status[# Top]

Measurements is agnostic to the precise interpretation of the uncertainty value, except that it must be small relative to the measurement value in order for the approximations made in the uncertainty propagation rules to be valid.  One option is to interpret the uncertainty as an upper bound on the standard deviation of the measurement under some Bayesian concept of its distribution; I would imagine that the propagation rules are sound with respect to this interpretation, but I have not formally verified this.  The rules are designed to account for the worst case of complete dependence among the inputs to each mathematical operation in the direction that produces the largest uncertainty in the result.  This can be unreasonably pessimistic in many scenarios, but the easy alternative assumption of independence of the inputs to every mathematical operation is badly unsound.  A better approach seen in some other tools is to assume a particular joint distribution on the set of inputs to a series of operations (e.g., independence may be reasonable in some scenarios), take (say) 1000 independent random samples from that joint distribution, parcel the components of these samples out to the individual inputs (thus representing each input as a list of 1000 samples), map every mathematical operation over these lists, and then compute the uncertainty of any measurement as the standard deviation of its list.  However, manipulating large lists of samples would likely cause severe scalability problems in the current implementation.

Measurements is currently best regarded as a proof of concept, since the sets of units and mathematical operations it supports are limited, it supports only one (pessimistic) uncertainty propagation model, and the representation of measurements as strings like "4.E-1 s^-1 m    [P9mZmZmZmZk/bGYgfrPzcf8BAAAAAA==]" (a value formatted for display and a dump of the internal state) is ugly.  With deeper knowledge of the OpenOffice / LibreOffice API, I might be able to hide the state dump.  I don't plan to make enhancements to the functionality of Measurements unless I become aware of significant demand.  My plans are limited to periodically updating Measurements to maintain compatibility with current versions of OpenOffice and LibreOffice if it doesn't become too much work.  As of 2020-08-30, I tested Measurements in libreoffice-calc- in Fedora 32 and it worked out of the box (ditto on an upstream build of OpenOffice 4.1.7 on 2020-09-12), but I believe there is a very rare bug if the string "ERROR" coincidentally appears in a base-64 dump.  I am considering making a new release to fix the bug and possibly make packaging improvements in response to changes to OpenOffice / LibreOffice since 2009.

Installation and usage[# Top]

The following instructions were written for in 2009, but I hope a similar procedure works now.

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  (If you are upgrading, remove the old package and restart first.)

Here is the UNO package for download.

FileSizeModification time
measurements-1.3.oxt313792009-09-15 22:41:20 +0000
measurements-1.2.oxt317492009-02-07 04:25:13 +0000
measurements-1.1.oxt304622008-01-08 02:04:41 +0000 21:31:16 +0000

Note: For the extension to install properly, you must have the file unoil.jar that contains the Java interfaces.  In Fedora, this file is in the main package; in Ubuntu, it comes in a separate package.

To use:

If you find bugs (which are almost certain to exist), please report them to me!

Measurements consists of:

Measurements comes with absolutely no warranty.

Version log[# Top]

Source repository[# Top]

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.

Matt McCutchen's Web SiteMeasurements for LibreOffice  (Top, Design and status, Installation and usage, Legal, Version log, Source repository, Bottom).  Email me about this page.
Modification time of this page's main source file: 2020-09-15 11:49:54 +0000
Except where otherwise noted, Matt McCutchen waives his copyright to the content of this site.  This site comes with absolutely no warranty.  Why?