The beer dataset contains 60 samples published by Norgaard et al. Recorded with a 30mm quartz cell on the undiluted degassed beer and measured from 1100 to 2250 nm (576 data points) in steps of 2 nm.

data(beer)

References

Norgaard, L., Saudland, A., Wagner, J., Nielsen, J. P., Munck, L., & Engelsen, S. B. (2000). Interval partial least-squares regression (iPLS): a comparative chemometric study with an example from near-infrared spectroscopy. Applied Spectroscopy, 54(3), 413--419.

Examples

data("beer") x.cal <- beer$xtrain dim(x.cal)
#> [1] 40 576
x.test <- beer$xtest dim(x.test)
#> [1] 20 576
y.cal <- beer$ytrain dim(y.cal)
#> [1] 40 1
y.test <- beer$ytest dim(y.test)
#> [1] 20 1
X <- rbind(x.cal, x.test) y <- rbind(y.cal, y.test) n <- nrow(y) set.seed(1001) samp.idx <- sample(1L:n, round(n * 0.7)) X.cal <- X[samp.idx, ] y.cal <- y[samp.idx] X.test <- X[-samp.idx, ] y.test <- y[-samp.idx]