Comparing Spectra with different math treatments

March 30, 2012

(This article was first published on NIR-Quimiometría, and kindly contributed to R-bloggers)

It is amazing the quantity of graphics you can develop with R, and how you can show and manage  these graphics. Here in the same plot we compare the raw demo spectra, treated with MSC, SNV and with the first derivative (differences between consecutive  data points). We can see how SNV and MSC look similar, but if you look to the Y  axis, they are different.
In the first derivative spectra there is a big peak of noise at 1100 nm. At this wavelength the detector change from “Si” to “PbSn”, so the difference in absorbance’s is quite high (from 1098 to 1100), so we have to exclude this area if we develop the calibration with the full spectrum range.

Using: par(mfrow=c(2,2)) opens a window, where we plot our spectra with the four different treatments.

To leave a comment for the author, please follow the link and comment on their blog: NIR-Quimiometría. offers daily e-mail updates about R news and tutorials on topics such as: Data science, Big Data, R jobs, visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web Scraping) statistics (regression, PCA, time series, trading) and more...

If you got this far, why not subscribe for updates from the site? Choose your flavor: e-mail, twitter, RSS, or facebook...


Comments are closed.


Mango solutions

plotly webpage

dominolab webpage

Zero Inflated Models and Generalized Linear Mixed Models with R

Quantide: statistical consulting and training




CRC R books series

Six Sigma Online Training

Contact us if you wish to help support R-bloggers, and place your banner here.

Never miss an update!
Subscribe to R-bloggers to receive
e-mails with the latest R posts.
(You will not see this message again.)

Click here to close (This popup will not appear again)