PLS regression on near infrared (NIR) spectra data
Hi, take a look on pls package and it's documentation, there are examples also for NIR data. http://mevik.net/work/software/pls.html Article form "Journal of Statistical Software" http://www.jstatsoft.org/v18/i02 Also "Caret" package can be used to evaluate pls and other regreesion models: http://caret.r-forge.r-project.org/Classification_and_Regression_Training.html Best regards, Andris On Tue, Mar 3, 2009 at 4:49 PM, Paulo Ricardo Gherardi Hein
<phein1980 at gmail.com> wrote:
Dear collegues, I? ve worked with near infrared (NIR) spectroscopy to assess chemical, physical, mechanical and anatomical properties of wood. I use "The Unscrambler" software to correlate the matrix of dependent variables (Y) with the matrix of spectral data (X) and I would like to migrate to R. The matrix of spectral variables is very large (2345 columns and n lines, where n = samples), so we used Partial Least Squares Regression to predict a variable y (content of cellulose, for instance) based on the spectral variables, which are the NIR wavelengths. I am new here (since jan2009) and up to now, I not seen anyone commenting about principal component analysis and regression PLS to analyze spectral information in R system. Sorry, I am a R starter... Anybody have any package, or trick to suggest me? Grateful for yours information! ?-- Paulo Ricardo Gherardi Hein PhD candidate at University of Montpellier 2 CIRAD - PERSYST Department Research unit: Production and Processing of Tropical Woods - TA B-40/16 73 rue Jean-Fran?ois Breton 34398 Montpellier Cedex 5, France phone: +33 4 67 61 44 51 skype: paulo_hein email: paulo.hein at cirad.fr ? ? ? ?[[alternative HTML version deleted]]
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