# The Graphical iPLS toolbox for MATLAB(TM)

by

Jesper Wagner

jesus.wagner@get2net.dk

### Introduction

Interval PLS is used to develop local PLS models on equidistant subintervals of the full spectrum region. Its main force in this context is to provide an overall picture of the relevant information in different spectral subdivisions and thereby narrowing the important spectral variables. Reference: L. Nørgaard, A. Saudland, J. Wagner, J.P. Nielsen, L. Munck and S.B. Engelsen., Interval Partial Least Squares Regression (iPLS): A Comparative Chemometric Study with an Example from Near-Infrared Spectroscopy, Applied Spectroscopy, 54, 2000.

### Method

Local PLS models are developed on spectral subintervals of equal width, and the prediction performance of these local models and the global (full spectrum) model is compared. The comparison is mainly based on the validation parameter RMSECV (Root Mean Squared Error of Cross Validation), but other parameters such as r2 (squared correlation coefficient), slope and offset are also consulted to ensure a comprehensive model overview.

### The iPLS toolbox for MATLAB is freely available

If you use the iPLS toolbox for MATLAB we would appreciate a reference to the toolbox. This is

The Graphical iPLS Toolbox for MATLAB, ver. 2.1, 2000
Jesper Wagner
KVL, Denmark
http://www.models.life.ku.dk/source/ipls/