| sdiag {mgcv} | R Documentation |
Extracts or modifies sub- or super- diagonals of a matrix.
sdiag(A,k=0) sdiag(A,k=0) <- value
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. |
A vector containing the requested diagonal, or a matrix with the requested diagonal replaced by value.
Simon N. Wood simon.wood@r-project.org
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