diag.ind. bio3d 2.3-0

Usage

diag.ind(x, n = 1, diag = TRUE)

Arguments

x: a matrix.
n: the number of elements from the diagonal to include.
diag: logical. Should the diagonal be included?

Description

Returns a matrix of logicals the same size of a given matrix with entries 'TRUE' in the upper triangle close to the diagonal.

Details

Basic function useful for masking elements close to the diagonal of a given matrix.

Value

Returns a matrix of logicals the same size of a given matrix with entries 'TRUE' in the upper triangle close to the diagonal.

References

Grant, B.J. et al. (2006) Bioinformatics 22, 2695--2696.

Examples

diag.ind( matrix(,ncol=5,nrow=5), n=3 )

      [,1]  [,2]  [,3]  [,4]  [,5]
[1,]  TRUE  TRUE  TRUE FALSE FALSE
[2,] FALSE  TRUE  TRUE  TRUE FALSE
[3,] FALSE FALSE  TRUE  TRUE  TRUE
[4,] FALSE FALSE FALSE  TRUE  TRUE
[5,] FALSE FALSE FALSE FALSE  TRUE

Author

Barry Grant

Diagonal Indices of a Matrix