Blog Archives

Preparing Spectrum to import into "ChemoSpec"

June 28, 2012
By
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.

Read more »

Olive Oil NIR/VIS Spectra – 001 (ChemSpec)

June 25, 2012
By
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 ...

Read more »

My first "ChemoSpec" spectra

June 21, 2012
By
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...

Read more »

Should I adjust the slope?

June 11, 2012
By
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...

Read more »

Improving Monitor statistics with the "UECLs"

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

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

Read more »

F-test to find UECLs

June 5, 2012
By
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...

Read more »

Removing "Y" outliers from the "Validation Set"

June 3, 2012
By
Removing "Y" outliers from the "Validation Set"

This is a new video about how to monitor and interpret statistics and graphics for validation. Removing "Y" outliers from Validation SetPrevious videos about the Monitor function  for validation:Should I adjust the Bias?Monitor: Adding "RER" and "...

Read more »

Exporting from Win ISI / Importing into R

May 29, 2012
By
Exporting from Win ISI / Importing into R

Chemometric software´s  have the option to export a matrix to a TXT file (in this case a constituents matrix), in a way we can import it easily into R, to work with. It is the first step to go into the R world.I use in this case Win ISI Soft...

Read more »

Mahalanobis distance with "R" (Exercice)

May 29, 2012
By
Mahalanobis distance with "R" (Exercice)

I have developed this exercise with Excel in another post for the same calculations , I am going to develop  it this time with  "R".    edad  long.  peso    mg.kg1    28 &n...

Read more »

Monitor: Adding "RER" and "RPD" statistics

May 25, 2012
By
Monitor: Adding "RER" and "RPD" statistics

I continue developing the Monitor function in R. The idea is to get statistics which help me to understand the performance of my model.Of course the validation set must be free of outliers (X or Y).I add this time two new statistics: RER and ...

Read more »