Determines the classifications corresponding to different numbers of groups
given merge pairs from hierarchical agglomeration.

## Arguments

- hcPairs
A numeric two-column matrix in which the *i*th row gives the minimum
index for observations in each of the two clusters merged at the
*i*th stage of agglomerative hierarchical clustering.

- G
An integer or vector of integers giving the number of clusters for which
the corresponding classfications are wanted.

## Value

A matrix with `length(G)`

columns, each column
corresponding to a classification. Columns are indexed by the character
representation of the integers in `G`

.

## Examples

```
hcTree <- hc(modelName="VVV", data = iris[,-5])
cl <- hclass(hcTree,c(2,3))
# \donttest{
par(pty = "s", mfrow = c(1,1))
clPairs(iris[,-5],cl=cl[,"2"])
clPairs(iris[,-5],cl=cl[,"3"])
# }
```