
CompPad is an OpenOffice.org / LibreOffice extension for performing unitsaware
engineering calculations within a Writer document, allowing calculations to be
documented using all of the resources of the Writer application. It has
functionality similar to Mathcad, but is not intended to be a Mathcad clone.
Rather, I hope it might prove more flexible and extensible, and that it might
encourage other free / opensource alternatives to a proprietary engineering
"Killer App."
 
CompPad allows you to create technical calculations in the form of
conventionallooking mathematical expressions using the OpenOffice.org equation
editor. This editor has a simple text syntax that some consider to be faster and
more intuitive than other equation editors. Then, with the click of a toolbar
icon, CompPad will evaluate the expressions and display the results, embedded in
your document. All of the features of OpenOffice.org are available for
documenting and formatting your document so that it can be presented with pride
to coworkers, customers, professors, etc.
NOTE: This page is fairly static. The most uptodate information may be found in the
wiki.
Example
Here is an example of how you might use CompPad. It is a simple
mechanical harmonic oscillator example based on the Wikipedia
topic . You
can download this example here:
example  harmonic oscillator.odt.
(Formulas rendered using mathimo.com)
 Install the CompPad extension (easy, see below.)
 Open a new OpenOffice.org Writer document. You should see a toolbar that
looks like this: .
 First we define the mass of the oscillator. Enter the following text in
the toolbar edit field
:
(without quotation marks)
"M:=10 kg"
 Press "enter" or click
.
The following formula will be created:
 Use the mouse to move the cursor to a point after the formula. Now you
can create another formula or edit text.
 Define the spring constant:
"K:= 4 lbf/inch"
 Calculate the natural frequency of the oscillator:
"f_n := 1 over {2 %pi} sqrt{ K over M}="
 To evaluate the expressions you've entered so far, click
. You will see that the last expression gets updated with the
result of the calculation:
Notice how the units of measure were handled automatically. Even though we
entered quantities in both SI and US Customary units, the correct solution was
computed.
 Define the amplitude of the oscillation:
"A:= 2 cm"
 Define position as a function of time:
"x(t) := A cos left( sqrt{K over M } t right)"
 Create a time vector with 21 elements, ranging from 0 to 1 s:
"t:={0 dotslow 20} over 20 s"
 Then calculate the position vector:
x_t:= x(t)
 To plot position vs. time:
"plotxy(t,x_t)"
 Finally, click
. You will see the following plot added to the document:
Now, you can add text, pictures, formatting, and other elements using all of
the features of OpenOffice.org Writer. If you need to change a parameter in
the calculation, you can make your changes using the equation editor, and then
to reevaluate the document.
CompPadDemo.odt demonstrates all the features of CompPad in a writer
document. Also, check out the example files.
Screenshots
Click thumbnails for fullsize image.
Installation
 Both Stable (featurecomplete) and unstable (developer snapshot) releases
are available HERE.
 Download the most recent .oxt from "Stable", if you are a new user or
from "Unstable", if you are more adventurous or require bleedingedge features.
 In OpenOffice.org or LibreOffice 3.x, installing the extension for the
first time should be as simple as opening the file using "File" > "Open".
 After installing, you will need to restart
OpenOffice.org / LibreOffice.
 If you are upgrading from a previous version of CompPad, the above procedure
may work. However, if it fails, Check the
FAQ
CompPad is an OpenOffice.org / LibreOffice extension implemented in Java. In
theory it should run on any platform that supports OpenOffice.org / LibreOffcie 3 and Sun Java
1.5 or higher. It is being developed under Ubuntu 10.05, NetBeans 6.9.1,
Openoffice 3.2 and Java 1.6.0_15. It should run in on Windows, Linux, OS X, and
other operating systems that support OOO/LibO and Java.
Using CompPad
 Try the example above
 See the User Guide,
which applies to version 0.3 and higher.
 For a document with an extensive list of examples, download
CompPadDemo.odt . This file demonstrates most of the features of CompPad and
should help you get started.
 Try changing the expressions in these examples, or create a new document with
your own expressions. If you get an error, doublecheck the offending formula.
 If you're stuck, check the FAQ
 If you're still stuck, check the
mailing list archive to see if your question has been answered.
 Email questions, bugreports and feature requests to the Mailing List .
Example Files
CompPadDemo.odt
is a document which contains examples of most CompPad features.
example  fluid mechanics.odt
Current Status
CompPad is currently in alpha release. It is quite usable, and has been
reportedly used to evaluate documents with hundreds of formulas. I expect
to finally move to a Beta release in the 0.3 branch (release 0.3.1.1)
Here are a few of the features that are supported in the most recent version:
 Singleline function definition
 Quick editing of formulas using edit field in toolbar.
 Real and Complex numbers, booleans, vectors and matrices
 Units of measure are handled in all quantities and calculations.
 Units are displayed according to the specified system of units. Options are
"SI","US","CGS".
 Support for alternate decimal separators  either "." or ","
 Basic operators including arithmetical, exponential, comparison, rounding,
trigonometric, logarithmic, exponential..
 Vector / matrix operators including transpose, multiply, Min, max, sum,
product. Scalar operators can also be applied to vectors.
 Basic XY plotting
 Complex variable names consisting of almost any combination of text or formula element.
 Changing expression color
 Blocking evaluation of an expression.
 Setting number of displayed significant figures or decimal places.
 import expressions from a text file.
If you require a certain feature for CompPad to be useful to you, please
let me know. I may be able to give it priority.
Development
CompPad is being actively developed. I have been making commits to
Subversion at least weekly as I add new features or fix bugs.
Following are a few features I hope to implement eventually:
 Import expressions from other documents
 Read from and write to cells in OpenOffice.org Calc.
 Solve blocks
 Function blocks
 Control stuctures (doloops, ifthenelse, etc.)
 More complete set of builtin functions and operators, including integrals and
derivatives.
 Symbolic operations, using
Maxima as a symbolic engine
 Localization
 Plugin framework for adding new functions, operators, etc.
 Web interface
A roadmap is located here:
Roadmap. However, it is not kept very current.
Contribute
Currently the best way to contribute is to try out CompPad, and post your
question and comments to the Mailing List. Your
comments help me know what is important to users. I would especially like to know how you would
like to use CompPad. If you require a certain feature in order for CompPad to be
useful to you, then let me know. I may be able to give it priority.
If you like CompPad, please let people know by posting a message in your blog,
in online forums, or other news outlets. If you don't like it, then ping the
dev list and tell me why!
If you find a discrepancy in the documentation on the Wiki, then feel free to
fix it yourself, or at least flag the problem with a comment, eg. "THIS SECTION
NEEDS MORE DETAILS" so myself or another contributor can correct the problem.
Translation work would be helpful. Spanish, Russian and Chinese would be
especially valuable, but anything would be welcomed.
License
Source code is provided under the terms of the GPL Ver. 3. It is available
through Subversion on the Sourceforge Project Page.
Copyright 2011. All Rights Reserved.

News
File Releases
Stable (feature complete)
Unstable (under development)

