Posts Tagged ‘ "R" Chemometrics ’

Hierarchical Cluster Analysis (ChemoSpec) – 02

July 19, 2012
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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...

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Monitor with R: Moisture in Sunflower Seeds Intact

July 18, 2012
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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...

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Hierarchical Cluster Analysis (ChemoSpec) – 01

July 17, 2012
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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 ...

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Olive vs. Sunflower oil Spectra – 002 (ChemoSpec)

July 1, 2012
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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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Preparing Spectrum to import into "ChemoSpec"

June 28, 2012
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Preparing Spectrum to import into "ChemoSpec"

In this video I show I to prepare a spectrum to import later into ChemoSpec:The software I use gives the option to export the spectrum as a TXT file.This file is open with Excel and saved as CSV, to import later with others into ChemoSpec.

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Olive Oil NIR/VIS Spectra – 001 (ChemSpec)

June 25, 2012
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Olive Oil NIR/VIS Spectra – 001 (ChemSpec)

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
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My first "ChemoSpec" spectra

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
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Should I adjust the slope?

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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Improving Monitor statistics with the "UECLs"

June 6, 2012
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Improving Monitor statistics with the "UECLs"

New Monitor Video:Improving Monitor statistics with the "UECLs"

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F-test to find UECLs

June 5, 2012
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F-test to find UECLs

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 SEP...

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