"R" Chemometrics

Shootout 2012: Test & Val Sets proyections

November 7, 2012 | jrcuesta

It is obvious (after seeing the spectra of the calibration set), that we have at least three clusters, and that this can be related with the concentration of the active ingredient in the tablets. If we see the scores in the PC1-PC2 score map we will se...
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Working with Shootout – 2012 in R (001)

October 29, 2012 | jrcuesta

I have downloaded (from the IDRC) the ASCI files of the Shootout 2012 (see: Shootout 2012 files), so I can work with the data  to develop a model and predict a Validation Set.For that task I have a "Calibration Set", and a  "Test Se...
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Looking to the PCA scores with GGobi

October 21, 2012 | jrcuesta

In this post I continue with the unsupervised exploration of oil spectra, which we have seen in previous post ( PCA with "ChemoSpec" - 001).In the manual "ChemoSpec:An R Package for Chemometric Analysis of Spectroscopic Data", (page 23) there is a brie...
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PCA with "ChemoSpec" – 001

October 20, 2012 | jrcuesta

In my last post about "ChemoSpec package" (Hierarchical Cluster Analysis (ChemoSpec) - 02), we saw the two cluster groups (one for olive oil, other for sunflower oil), and also another sub-clusters for the sunflower oil.Continue reading the manual "Che...
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PLS2 with "R"

September 22, 2012 | jrcuesta

I´ve been working these days with PLS2 calibrations with a chemometric software called “Unscrambler” with a data set called “jam”. I said “can I develop PLS2 models with R?”.I look in the book “Introduction to Multivariate Statistical An...
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Monitor: Using category labels

July 26, 2012 | jrcuesta

I´ve been checking recently the performance of a calibration of compound feed with  a set of samples (15): 3 samples of hen feed, 3 of pig feed, 3 of chicken feed, 3 of ovine feed and 3 of cattle feed.The idea is to check if the calibration predi...
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Olive Oil NIR/VIS Spectra – 001 (ChemSpec)

June 25, 2012 | jrcuesta

I continue with the practicing with ChemSpec, and this time I import seven spectra of olive oil. This time I have been more careful and I have the frequency column as numeric form the CSV file. Once I have the spectra (with and offset):Take in account ...
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My first "ChemoSpec" spectra

June 21, 2012 | jrcuesta

I’ve been this week trying to import some spectra to ChemoSpec (R Package), at the beginning I had problems generating the “csv”  files, and the function getManyCsv did not recognize the files. I did not have properly configured the regional...
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Should I adjust the slope?

June 11, 2012 | jrcuesta

I add a new video “Should I adjust the slope”, where a new part of script is added to the monitor function.  I don´t recommend adjusting the slope, but there are circumstances where it is necessary:Suppose you have an equation, but not the ca...
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F-test to find UECLs

June 5, 2012 | jrcuesta

I have fixed the link to the video "Removing Y outliers from the validation set" and it´s time to see what could be the next step to the function. As we know the RMSEP is the sum of the explained (BIAS) and unexplained error (SEP). We get also the ...
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