| sdiag {mgcv} | R Documentation |
Extract or modify diagonals of a matrix
Description
Extracts or modifies sub- or super- diagonals of a matrix.
Usage
sdiag(A,k=0)
sdiag(A,k=0) <- value
Arguments
A |
a matrix |
k |
sub- (negative) or super- (positive) diagonal of a matrix. 0 is the leading diagonal. |
value |
single value, or vector of the same length as the diagonal. |
Value
A vector containing the requested diagonal, or a matrix with the requested diagonal replaced by value.
Author(s)
Simon N. Wood simon.wood@r-project.org
Examples
require(mgcv)
A <- matrix(1:35,7,5)
A
sdiag(A,1) ## first super diagonal
sdiag(A,-1) ## first sub diagonal
sdiag(A) <- 1 ## leading diagonal set to 1
sdiag(A,3) <- c(-1,-2) ## set 3rd super diagonal
[Package mgcv version 1.9-1 Index]