On 7/30/07, Alex Brown [EMAIL PROTECTED] wrote:
When at, label chains contain duplicate at values, axis ticks are
dropped. I believe this is handled incorrectly for Date ats in
lattice 0.15-4 when compared to how it is handled for numeric, or for
dates in base plot. This can result in mis-labelled axes in some
circumstances. I have included executable examples.
R: 2.5.0
numeric base plot:
plot(1:10, axes=F); axis(1, at=c(2,4,4,6), labels=letters[1:4])
shows labels a, b, d
date scale in base plot:
plot((as.Date(2007-01-01) + 1:10), 1:10, axes=F); axis(1, at=
(as.Date(2007-01-01)+c(2,4,4,6)), labels=letters[1:4])
shows labels a, b, d
However,
foo = as.Date(2007-01-01)
plot(foo + 1:10, 1:10, axes = FALSE)
axis.Date(1, at = foo + c(2,4,4,6), labels = letters[1:4])
Error in axis(side, at = z, labels = labels, ...) :
'at' and 'labels' lengths differ, 3 != 4
And this code is used almost unchanged in lattice, leading to
str(lattice:::formattedTicksAndLabels.Date(range(foo + 1:10), at = foo + c(2,
4, 4, 6), labels = letters[1:4]))
List of 4
$ at : num [1:3] 13516 13518 13520
$ labels : chr [1:4] a b c d
$ check.overlap: logi FALSE
$ num.limit: num [1:2] 13515 13524
That is, 'at' is now of length 3 (and unlike axis.Date, this does not
subsequently cause an error, which probably would have been
preferable).
I will add a fix.
-Deepayan
numeric scale in lattice plot
xyplot(1:10 ~ 1:10, scales=list(x=list(relation=free, at=c
(2,4,4,6), labels=list(letters[1:4]
shows labels a, b, d
date scale in lattice plot
xyplot(1:10 ~ (as.Date(2007-01-01) + 1:10) , scales=list(x=list
(relation=free, at=list(as.Date(2007-01-01)+c(2,4,4,6)),
labels=list(letters[1:4]
shows labels a, b, c
Since this results in label c being placed at position 6, not 4, I
feel this is a bug.
-Alex Brown
__
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
