search for: emptysetfunc

...of course, is non-NULL: is.null(character(0)) # FALSE So, how can we test if a vector is, say, character(0)? The following doesn't (seem to) work: x <- character(0) x == character(0) # logical(0) More snooping led to the following: wiki.r-project.org/rwiki/doku.php?id=tips:surprises:emptysetfuncs and at the bottom of the page it says "logical(0) is an empty set, thus is TRUE". However, I get isTRUE(logical(0)) # FALSE but, on the other hand, all.equal(x, character(0)) # TRUE This would seem to be the solution, but am I missing something? and in particular, is there an el...

Tony Plate <tplate <at> acm.org> writes: > > Since the virtue and reliability of Wikis was brought up, I created a R > Wiki page for this at > http://www.sciviews.org/_rgui/wiki/doku.php?id=beginners:surprises:emptysetfuncs > > > Anyone: please correct errors and improve it! > > Tony Plate > OK, now I have another question: I see a wiki at http://fawn.unibw-hamburg.de/cgi-bin/Rwiki.pl?RwikiHome administered by Detlef Steuer I see another at http://www.sciviews.org/_rgui/wiki/doku.php (P...

Tony Plate <tplate <at> acm.org> writes: > > Since the virtue and reliability of Wikis was brought up, I created a R > Wiki page for this at > http://www.sciviews.org/_rgui/wiki/doku.php?id=beginners:surprises:emptysetfuncs > > > Anyone: please correct errors and improve it! > > Tony Plate > OK, now I have another question: I see a wiki at http://fawn.unibw-hamburg.de/cgi-bin/Rwiki.pl?RwikiHome administered by Detlef Steuer I see another at http://www.sciviews.org/_rgui/wiki/doku.php (P...

Hello again, I have a question on who sum() handle the NA values. > sum(c(NA, 1), na.rm = TRUE) [1] 1 I understand this. However could not agree with following: > sum(c(NA, NA), na.rm = TRUE) [1] 0 Where this '0' is coming from? Should not it be NA itself? Thanks and regards,

Hi all, Can anyone explain why the following use of the subset() function produces a different outcome than the use of the "[" extractor? The subset() function as used in density(subset(mydf, ht >= 150.0 & wt <= 150.0, select = c(age))) appears to me from documentation to be equivalent to density(mydf[mydf$ht >= 150.0 & mydf$wt <= 150.0, "age"])