is.null.DN
Are the Dimnames dn NULL-like ?
Description
Are the dimnames
dn
NULL
-like?
is.null.DN(dn)
is less strict than is.null(dn)
, because it is also true (TRUE
) when the dimnames dn
are “like” NULL
, or list(NULL,NULL)
, as they can easily be for the traditional R matrices (matrix
) which have no formal class
definition, and hence much freedom in how their dimnames
look like.
Usage
is.null.DN(dn)
Arguments
dn |
Value
Note
This function is really to be used on “traditional” matrices rather than those inheriting from Matrix
, as the latter will always have dimnames list(NULL,NULL)
exactly, in such a case.
Author(s)
Martin Maechler
See Also
Examples
m <- matrix(round(100 * rnorm(6)), 2,3); m1 <- m2 <- m3 <- m4 <- m dimnames(m1) <- list(NULL, NULL) dimnames(m2) <- list(NULL, character()) dimnames(m3) <- rev(dimnames(m2)) dimnames(m4) <- rep(list(character()),2) m4 ## prints absolutely identically to m stopifnot(m == m1, m1 == m2, m2 == m3, m3 == m4, identical(capture.output(m) -> cm, capture.output(m1)), identical(cm, capture.output(m2)), identical(cm, capture.output(m3)), identical(cm, capture.output(m4)))
Copyright (©) 1999–2012 R Foundation for Statistical Computing.
Licensed under the GNU General Public License.