A History of PLS_Toolbox

I started graduate school at the University of Washington Department of Chemical Engineering in the Fall of 1985. Sometime around Fall of 1986 somebody showed me MATLAB. Wow. That was the last day I ever wrote anything in Basic or Fortran–it was MATLAB from there on out. In 1987 I finished my MS in ChemE and started on a new project which became my dissertation, “Adapting Multivariate Analysis for Modeling and Monitoring Dynamic Systems“. In order to do this research I needed to develop multivariate analysis routines and process simulations, so MATLAB was the logical tool of choice.

At some point late in 1989 I realized that I had created a significant number of routines that might be of use to other researchers. I collected these functions, wrote sensible help files for them, and wrote a brief manual. I’d been working a lot with Partial Least Squares (PLS) regression, and the bulk of the functions I’d created related to that, so I decided (for better or worse) to call it PLS_Toolbox. Why the underscore? Honestly, I don’t remember. It may have had to do with inability of some operating systems to deal with path names that included whitespace. And I didn’t like running it together, PLSToolbox, because that reads like PL Stoolbox, and I didn’t like the connotation.

So in the fall of 1989 I printed up some manuals for PLS_Toolbox 1.0 and started distributing it around the Chemical Engineering Department and the Center for Process Analytical Chemistry. The rest, as they say, is history. After graduating from UW in 1991, I continued to update PLS_Toolbox and distribute it under the company Eigenvector Technologies. Battelle Pacific Northwest National Laboratory, my employer, had no interest in it. So I worked on it evenings and weekends and continued to release updates.

I founded Eigenvector Research, Inc. with Neal Gallagher on January 1, 1995, though PLS_Toolbox still came out under Eigenvector Technologies until version 2.0. A complete list of releases is given below.

PLS_Toolbox 1.0 late 1989 or early 1990
PLS_Toolbox 1.1 1990
PLS_Toolbox 1.2 1991
PLS_Toolbox 1.3 1993
PLS_Toolbox 1.4 1994 (July)
PLS_Toolbox 1.5 1995 (July-added author Neal B. Gallagher)
PLS_Toolbox 2.0 1998 (April-first version under Eigenvector Research)
PLS_Toolbox 2.1 2000 (November)
PLS_Toolbox 3.0 2002 (December–added authors Rasmus Bro and Jeremy M. Shaver)
PLS_Toolbox 3.5 2004 (August–added authors Willem Windig and R. Scott Koch)
PLS_Toolbox 4.0 2006 (May)
PLS_Toolbox 4.1 2007 (June)
PLS_Toolbox 4.2 2008 (January)

The release of PLS_Toolbox 4.2 this month brings the total number of versions to 13. We’ve been pretty stingy with our version numbers, changing them in increments of only 0.1 even when we added significant functionality. In other software companies PLS_Toolbox 4.2 would probably be known as version 9.1 or something like that.

Hope you enjoyed the history lesson, and thanks for checking in!

BMW