# CorGroups: Correlation Matrix for Sub-groups In StatDA: Statistical Analysis for Environmental Data

 CorGroups R Documentation

## 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 <P.Filzmoser@tuwien.ac.at> 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.