| octane {rrcov} | R Documentation |
Octane data
Description
The octane data contains near infrared absorbance spectra (NIR) of
n=39 gasoline samples over p=226 wavelengths ranging
from 1102 nm to 1552 nm with measurements every two nanometers. For
each of the 39 production gasoline samples the octane number y was measured.
Six of the samples (25, 26, and 36-39) contain added alcohol.
Usage
data(octane)Format
A data frame with 39 observations and 227 columns, the wavelengts are
by column and the first variable is the dependent one (y).
Source
K.H. Esbensen, S. Schoenkopf and T. Midtgaard Multivariate Analysis in Practice, Trondheim, Norway: Camo, 1994.
References
M. Hubert, P. J. Rousseeuw, K. Vanden Branden (2005), ROBPCA: a new approach to robust principal components analysis, Technometrics, 47, 64–79.
P. J. Rousseeuw, M. Debruyne, S. Engelen and M. Hubert (2006), Robustness and Outlier Detection in Chemometrics, Critical Reviews in Analytical Chemistry, 36(3–4), 221–242.
Examples
data(octane)
octane <- octane[, -1] # remove the dependent variable y
pca=PcaHubert(octane, k=10)
screeplot(pca, type="lines")
pca2 <- PcaHubert(octane, k=2)
plot(pca2, id.n.sd=6)
pca7 <- PcaHubert(octane, k=7)
plot(pca7, id.n.sd=6)