sn (version 2.0.0)

wines: Piedmont wines data

Description

Data refer to chemical properties of 178 specimens of three types of wine produced in the Piedmont region of Italy.

Usage

data(wines)

Format

A data frame with 178 observations on the following 28 variables.

wine	wine name (categorical, levels: Barbera, Barolo, Grignolino)
alcohol	alcohol percentage (numeric)
sugar	sugar-free extract (numeric)
acidity	fixed acidity (numeric)
tartaric	tartaric acid (numeric)
malic	malic acid (numeric)
uronic	uronic acids (numeric)
pH	pH (numeric)
ash	ash (numeric)
alcal_ash	alcalinity of ash (numeric)
potassium	potassium (numeric)
calcium	calcium (numeric)
magnesium	magnesium (numeric)
phosphate	phosphate (numeric)
cloride	chloride (numeric)
phenols	total phenols (numeric)
flavanoids	flavanoids (numeric)
nonflavanoids	nonflavanoid phenols (numeric)
proanthocyanins	proanthocyanins (numeric)
colour	colour intensity (numeric)
hue	hue (numeric)
OD_dw	\(OD_{280}/OD_{315}\) of diluted wines (numeric)
OD_fl	\(OD_{280}/OD_{315}\) of flavanoids (numeric)
glycerol	glycerol (numeric)
butanediol	2,3-butanediol (numeric)
nitrogen	total nitrogen (numeric)
proline	proline (numeric)
methanol	methanol (numeric)

Details

The data represent 27 chemical measurements on each of 178 wine specimens belonging to three types of wine produced in the Piedmont region of Italy. The data have been presented and examined by Forina et al. (1986) and were freely accessible from the PARVUS web-site until it was active. These data or, more often, a subset of them are now available from various places, including some R packages. The present dataset includes all variables available on the PARVUS repository, which are the variables listed by Forina et al. (1986) with the exception of ‘Sulphate’. Moreover, it reveals the undocumented fact that the original dataset appears to include also the vintage year; see the final portion of the ‘Examples’ below.

References

Forina M., Armanino C., Castino M. and Ubigli M. (1986). Multivariate data analysis as a discriminating method of the origin of wines. Vitis 25, 189--201.

Examples

# NOT RUN {
data(wines)
pairs(wines[,c(2,3,16:18)], col=as.numeric(wines$wine))
#
code <- substr(rownames(wines), 1, 3)
table(wines$wine, code)
#
year <- as.numeric(substr(rownames(wines), 6, 7))
table(wines$wine, year)
# coincides with Table 1(a) of Forina et al. (1986)
# }