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Usage:
dmat(n,val), n > 0 integer, val a REAL, CHARACTER or LOGICAL scalar
dmat(vec), vec a REAL, CHARACTER or LOGICAL vector.
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Keywords:
matrix algebra, variables
Usage
dmat(n,val), where n is a positive integer and val is a scalar
(length(val) = 1), produces an n by n diagonal matrix with val down the
diagonal.
dmat(a) where a is a vector of length n, a n by 1 matrix, or a 1 by n
matrix, produces a n by n diagonal matrix with the elements of a down
the diagonal.
Note: This is a sort of inverse to diag() which extracts the diagonal
elements of a matrix.
Example
Example:
Cmd> iden5 <- dmat(5,1); iden5 # or dmat(rep(1,5))
(1,1) 1 0 0 0 0
(2,1) 0 1 0 0 0
(3,1) 0 0 1 0 0
(4,1) 0 0 0 1 0
(5,1) 0 0 0 0 1
This is the 5 by 5 identity matrix
Cross references
See also diag().
Gary Oehlert
2005-08-12