R: Split Matrix by Clusters and Return Lower Triangular Parts as...

lower.tri.vector {MESS} | R Documentation

## Split Matrix by Clusters and Return Lower Triangular Parts as Vector

### Description

Split a matrix into block diagonal sub matrices according to clusters and combine the lower triangular parts into a vector

### Usage

    lower.tri.vector(x, cluster = rep(1, nrow(x)), diag = FALSE)

### Arguments

`x` | a square matrix
`cluster` | numeric or factor. Is used to identify the sub-matrices of `x` from which the lower triangular parts are extracted. Defaults to the full matrix.
`diag` | logical. Should the diagonal be included?

### Value

Returns a numeric vector containing the elements of the lower triangular sub matrices.

### Author(s)

Claus Ekstrom claus@ekstroem.dk

### See Also

`lower.tri`

### Examples

    m <- matrix(1:64, ncol=8)
    cluster <- c(1, 1, 1, 1, 2, 2, 3, 3)
    lower.tri.vector(m, cluster)

[Package MESS version 0.5.6 Index]