Checking validation statistics (Monitor function 030220139)
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Articles by jrcuesta
Looking to boxplots (Shootout 2012)
Boxplots are a nice way to compare the three sample sets of the Shoot-out 2012 data files.There is a category variable (Set) in the data frame with the labels (Cal = Training Set, Test = Test Set and Val = Validation Set). # IMPORTING THE SAMPLE SETS #... [Read more...]
Standard Normal Variate (SNV: Other way)
This is another way to pre-treat aspectra set with the SNV math-treatment (Standard Normal Variate). You can see the other one in the post : "Standard Normal Variate (SNV)".In this post, I use the R function "sweep".library(ChemometricsWithR)#in a... [Read more...]
"R" : Identifying peaks
The function "identify" from "R", is very useful to check the spectrum for peaks or areas of interest. I use it here to see the wavelength with the highest variability in the Shootout-2012 Calibration Set. This wavelength has a high variabi...
VIDEO: Working with ChemoSpec (HCA with the scores)
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Shootout 2012 : first PLS regressions
It´s time to start developing some regressions in order to find the best math treatment, the best number of terms, the best spectral regions, the best regression method,....This time I´m working with the PLS package in R, and just to make ...
VIDEO: Looking to the regression coefficients in R
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VIDEO: Looking to the loadings in R
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"Sample Sets" plots (Shootout-2012)
Histograms of all the sample sets together and individuallyRaw SpectraSpectra treated with MSC (Multiple Scatter correction)Spectra treated with SG filters
Shootout 2012: Test & Val Sets proyections
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...
Working with Shootout – 2012 in R (001)
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...
Looking to the PCA scores with GGobi
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...
PCA with "ChemoSpec" – 001
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...
PLS2 with "R"
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...
Monitor: Using category labels
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...
Hierarchical Cluster Analysis (ChemoSpec) – 03
It is clear that we can discriminate between olive oil and sunflower oil, but let´s see the reason for the sub-clusters in the sunflower oil.Samples sflw6da, sflw7da, sflw8da, sflw9da, sflw10da are refined sunflower, so it is filtered and processed, t...
Hierarchical Cluster Analysis (ChemoSpec) – 02
This is the second derivative spectra of the raw spectra we have sawn in the post: "Hierarchical Cluster Analysis (ChemoSpec) - 01". In that post we saw some clusters, but the distance between the clusters was not high, so it was clear that some m...
Monitor with R: Moisture in Sunflower Seeds Intact
I had the opportunity today to check the performance of a calibration (moisture in intact sunflower seed in reflectance).This is always a exciting moment: Does the performance of the calibration for the new validation set is as expected duri...
Hierarchical Cluster Analysis (ChemoSpec) – 01
I have been in previous post using the ChemoSpec package for some oil data (olive and sunflower). My spectra has now a range from 1100nm to 2200nm and is raw (not treated mathematically) . I want to start using the ChemoSpec package to start using the ...
Olive vs. Sunflower oil Spectra – 002 (ChemoSpec)
I add other data set of “sunflower oil” to import together with the olive oil into ChemoSpec R package. Before, as I showed in a video (Preparing spectra to import into ChemoSpec), every sample has been acquired with a NIR instrument (in transmitta...
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