diagonal: Extract diagonal terms from a variety of matrix types
Description
Extract diagonal terms from a variety of matrix types
Usage
diagonal(x, indices = NULL)
## S3 method for class 'default':
diagonal(x, indices = NULL)
Arguments
x
A sqaure matrix
indices
specifies a subset of the diagonal using a character vector of
names, a logical vector or integer indices. The default (NULL)
implies all elements.
Value
a named vector containing the diagonal elements.
Details
Insists that input matrix is square. Uses the 'diagonal'
attribute when available and has specialised handling of ff,
big.matrix, dgCMatrix matrices. Does not check that row and
colunm names are identical for those matrix clases (unlike the base
diag function, but always uses rownames.