R: Applies a function to all pairs of columns

colpairs {gclus} | R Documentation

## Applies a function to all pairs of columns

### Description

Given an nxp matrix `m` and a function `f`, returns the pxp matrix got by applying `f` to all pairs of columns of `m` .

### Usage

    colpairs(m, f, diag = 0, na.omit = FALSE, ...)

### Arguments

`m` | a matrix
`f` | a function of two vectors, which returns a single result.
`diag` | if supplied, this value is placed on the diagonal of the result.
`na.omit` | If `TRUE`, rows with missing values are omitted for each pair of columns.
`...` | argments are passed to `f`.

### Value

a matrix matrix got by applying `f` to all pairs of columns of `m` .

### Author(s)

Catherine B. Hurley

### See Also

`gave`, `partition.crit`, `order.single`,`order.endlink`

### Examples

    data(state)
    state.m <- colpairs(state.x77,
    function(x,y)  cor.test(x,y,"two.sided","kendall")$estimate, diag=1)
    state.col <- dmat.color(state.m)
    # This is equivalent to state.m <- cor(state.x77,method="kendall")

    layout(matrix(1:2,nrow=1,ncol=2))
    cparcoord(state.x77, panel.color= state.col)
    # Get rid of the panels with lots of line crossings (yellow) by reorderings
    cparcoord(state.x77, order.endlink(state.m), state.col)
    layout(matrix(1,1))

    # m is a homogeneity measure of each pairwise variable plot
    m <- -colpairs(scale(state.x77), gave)

    o<- order.single(m)
    pcols = dmat.color(m)
    # Color panels by level of m and reorder variables so that
    # pairs with high m are near the diagonal.
    cpairs(state.x77,order=o, panel.colors=pcols)

    # In this case panels showing either of Area or Population
    # exhibit the most clumpiness because these variables
    # are skewed.

[Package gclus version 1.3.1 Index]