is.null.DN: Are the Dimnames 'dn' NULL-like ?

Description Usage Arguments Value Note Author(s) See Also Examples

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

1

Arguments

dn

dimnames() of a matrix-like R object.

Value

logical TRUE or FALSE.

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

is.null, dimnames, matrix.

Examples

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
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)))


Search within the Matrix package
Search all R packages, documentation and source code

Questions? Problems? Suggestions? or email at ian@mutexlabs.com.

Please suggest features or report bugs with the GitHub issue tracker.

All documentation is copyright its authors; we didn't write any of that.