Hi Paulo, You might also want to look at something like the glmnet package (Friedman, Hastie, and Tibshirani). This carries out penalized regression, is designed to work with high numbers of predictors/inputs/columns and relatively few samples/obervations/rows, and is very fast.
See: http://www-stat.stanford.edu/~hastie/Papers/glmnet.pdf HTH, Mark. Paulo Ricardo Gherardi Hein 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-François Breton 34398 Montpellier Cedex 5, France > phone: +33 4 67 61 44 51 > skype: paulo_hein > email: paulo.h...@cirad.fr > > [[alternative HTML version deleted]] > > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > -- View this message in context: http://www.nabble.com/PLS-regression-on-near-infrared-%28NIR%29-spectra-data-tp22311467p22328510.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
