R: Various utility functions

vec2distm {gclus} | R Documentation

## Various utility functions

### Description

`vec2distm` converts a vector to a distance matrix.

`vec2dist` converts a vector to a `dist` structure.

`lower2upper.tri.inds` is the same as `lower.to.upper.tri.inds` from package cluster. It computes an index vector for extracting or reordering a lower triangular matrix that is stored as a contiguous vectors.

`diag.off` returns a vector of off-diagonal elements of a matrix. `off` specifies the distance above the main (0) diagonal.

`clus2memship` converts a list whose ith element contains the indices of objects in the ith cluster into a vector whose ith element gives the cluster number of the ith object.

`memship2clus` converts a vector whose ith element gives the cluster number of the ith object into a list whose ith element contains the indices of objects in the ith cluster.

### Usage

    vec2distm(vec)
    vec2dist(vec)
    lower2upper.tri.inds(n)
    diag.off(m,off=1)
    clus2memship(clusters)
    memship2clus(memship)

### Arguments

`vec` | is a vector.
`n` | is an integer > 1.
`m` | is a matrix.
`clusters` | is a list whose ith element contains the indices of the objects belonging to the ith cluster.
`off` | is an integer specifying the distance above the main (0) diagonal.
`memship` | is a vector whose ith element gives the cluster number of the ith object.

### Author(s)

Catherine B. Hurley

### See Also

`dist`, `diag`.

### Examples

    vec <- 1:15
    vec2distm(vec)
    vec2dist(vec)
    diag.off(vec2distm(vec))
    lower2upper.tri.inds(5)
    clus2memship(list(c(1,3,5),c(2,6),4))
    memship2clus(c(1,3,4,2,1,4,2,3,2,3))

[Package gclus version 1.3.1 Index]