Matrix (version 1.2-1)

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 Rmatrices (matrix) which have no formal class definition, and hence much freedom in how their dimnames look like.

Usage

is.null.DN(dn)

Arguments

dn

dimnames() of a matrix-like Robject.

Value

• logical TRUE or FALSE.

See Also

is.null, dimnames, matrix.

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)))