CAPCA
CAPCA is an add-in to Microsoft Excel that allows you to carry out Principal Components Analysis (PCA), Correspondence Analysis (CA) and Metric Scaling (MS) fully integrated with Excel. The program reads the data from your worksheets and produces additional worksheets with tables and statistics showing the result of the analysis as well as a number of charts to illustrate it.
History
The background for CAPCA was a DOS based program in Pascal called Kvark performing PCA and CA analyses that I wrote in 1989. The program was abandoned as Erwin Scollar’s successful program Basp and later WinBasp developed during the first half of the nineties. Both Kvark and Basp/Winbasp, however, were hampered by tedious data input procedures and a lack of efficient import facilities for data.
The advantage of a program for multivariate analyses within Excel appeared rather obvious, and around 2002, I made a first attempt to create CAPCA. The program was primarily used internally at the department, although it was disseminated to a few external colleagues as well. In 2005, I decided to make it generally available. It was launched as version 1, followed in 2007 by version 2 (version 2.1 in 2010 and version 2.2 in 2012).
Version 3.0 was originally intended to be a minor revision with a few improvements, partly from comments received from users. This was not to be, however. Looking at the code for the first time in two years, I realised that over the years of development it had ended up as a spaghetti junction code. Further, I was far from happy with the structure of the user interface. As a result, I completely rewrote the code, and created a new layout and functionality of the user interface.
Version
3.1 has a couple of new features. One is an improved data entry method for
Metric Scaling. You can now enter qualitative variables straight away as text.
The second feature is that you can use metric scaling to reduce three or more
principal axes to a two-dimensional plot in order to facilitate the
interpretation of the result of an analysis.
Requirements
You
have to use a 32-bit version of Excel. The variable declarations in VBA are
entirely different in the 64-bit version of Excel and hence the code is
incompatible. I have no plans for writing a 64-bit version.
CAPCA is written using the built in VBA programming language in Excel. The version of Excel used is 14 (2010). I have not had the possibility to test the program using newer versions, but I expect that it should work without problems. Should you come across errors I would appreciate if you will let me know.
The code is not password protected, and you are welcome to browse through it and make changes if you like. Should you make regular improvements to the program, I would appreciate if you inform me.
To be able to run version 3.1 of CAPCA you have to have Microsoft Office 2007 or later. If you have Excel 2003, you have to use version 2.11. You can download 2.11 for both Office 2003 and 2007.