Trying to find high content gypsum samples (part 2)

 If you have read the previous post (Trying to find high content gypsum samples), now it is time for the fine tuning in a visual way. I take apart the samples  with a value higher than a certain correlation (0.70 in this case), and the other samples goes to a new sample set, this way I hope to have the samples with high and low or no gypsum content in another. Finally, I plot them together and have a look.

cor3SG1 <- which(corSG1 > 0.70)
explore1 <- lucas_spain$spcnir_SG[cor3SG1, ]
explore2 <- lucas_spain$spcnir_SG[-cor3SG1, ]
matplot(colnames(lucas_spain$spcnir_SG),

        t(explore1), type = "l",lty =3, 

        xlab = "wavelength", ylab = "Absorbance", 

        col = "red", ylim = c(-0.025, 0.025))
par(new = TRUE)
matplot(colnames(lucas_spain$spcnir_SG), 

        t(explore2), type = "l", lty =3, 

        xlab = "wavelength", ylab = "Absorbance", 

        col = "blue",ylim = c(-0.025, 0.025))

We can have a closer view where the differences are more clear:

Now we can study apart the blue samples (low or no gypsum content) looking for other groupings and the red ones (gypsum content).