Comparing Spectra and Coefficients (Shootout 2002 NIR with R)

We can check the differences between the instruments 1 and 2 more in different ways. One could be to select 5 samples, and compare their spectra scanned in Instrument 1 and scanned in instrument 2. In this case I select from the training set samples 10,20,30,40 and 50.
The samples look like this:

But the best to see the differences, is to substract the spectra, so I made some substractions:
dif1<-selected[1,]-selected[6,]
dif2<-selected[2,]-selected[7,]
dif3<-selected[3,]-selected[8,]
dif4<-selected[4,]-selected[9,]
dif5<-selected[5,]-selected[10,]
and combined them:
dif<-rbind(dif1,dif2,dif3,dif4,dif5)
Now we can see the spectra of the differences (quite similar for the 5):

 

 

When developing the models (mod 1 and mod 2), we obtain the regression coefficient, which are like a spectra, so we can compare them:

 

 

and also substract them:

 

to obtain some conclussions.