CorGroups: Correlation Matrix for Sub-groups

In StatDA: Statistical Analysis for Environmental Data

Correlation Matrix for Sub-groups

Description

The correlation matrix for sub-groups of data is computed and displayed in a graphic.

Usage

CorGroups(dat, grouping, labels1, labels2, legend, ndigits = 4,
method = "pearson", ...)

Arguments

dat	data values (probably log10-transformed)
grouping	factor with levels for different groups
labels1, labels2	labels for groups
legend	plotting legend
ndigits	number of digits to be used for plotting the numbers
method	correlation method: "pearson", "spearman" or "kendall"
...	will not be used in the function

Details

The corralation is estimated with a non robust method but it is possible to select between the method of Pearson, Spearman and Kendall. The groups must be provided by the user.

Value

Graphic with the different sub-groups.

Author(s)

Peter Filzmoser <[e-mail]> http://cstat.tuwien.ac.at/filz/

References

C. Reimann, P. Filzmoser, R.G. Garrett, and R. Dutter: Statistical Data Analysis Explained. Applied Environmental Statistics with R. John Wiley and Sons, Chichester, 2008.

Examples

data(chorizon)
x=chorizon[,c("Ca","Cu","Mg","Na","P","Sr","Zn")]

#definition of the groups
lit=chorizon[,"LITO"]
litolog=rep(NA, length(lit))
litolog[lit==10] <- 1
litolog[lit==52] <- 2
litolog[lit==81 | lit==82 | lit==83] <- 3
litolog[lit==7] <- 4
litolog <- litolog[!is.na(litolog)]
litolog <- factor(litolog, labels=c("AB","PG","AR","LPS"))

op <- par(mfrow=c(1,1),mar=c(0.1,0.1,0.1,0.1))
CorGroups(log10(x), grouping=litolog, labels1=dimnames(x)[[2]],labels2=dimnames(x)[[2]],
legend=c("Caledonian Sediments","Basalts","Alkaline Rocks","Granites"),ndigits=2)
par(op)

StatDA documentation built on June 7, 2023, 6:26 p.m.