[R] 'levelplot' with an option 'at'

[Martina Pavlicova]

Hi all,
I encountered a difference between versions 1.6.1 and 1.7.0 when using
levelplot with an option 'at'. Here are the specs of the two platforms
used:

> R.version
         _
platform sparc-sun-solaris2.8
arch     sparc
os       solaris2.8
system   sparc, solaris2.8
status
major    1
minor    6.1
year     2002
month    11
day      01
language R

> R.version
         _
platform i686-pc-linux-gnu
arch     i686
os       linux-gnu
system   i686, linux-gnu
status
major    1
minor    7.0
year     2003
month    04
day      16
language R


I created an easy example of two levelplots (one without an option 'at'
and one with an option 'at') which I run through version 1.6.1. The plot
are called:
        version161.without_at.jpg
        version161.with_at.jpg

After update to version 1.7.0, I run the same two plots and I got the
following files:
        version170.without_at.jpg
        version170.with_at.jpg
When I don't include the option 'at' into a levelplot, the plots
version161.without_at.jpg and version170.without_at.jpg are similar
(differ only in labels for contours). BUT if I include the option 'at',
version 1.7.0 produces very different picture which I believe is wrong
(compare files version161.with_at.jpg and version170.with_at.jpg). WHY is
that? Am I missing something?

I have attached all 4 plots and also the commands I used to create the
small example.

Thank you for all your help.

Martina Pavlicova

---------------------------------------------------------------------
library(lattice)

x <- row(matrix(NA,11,11))-6
y <- col(matrix(NA,11,11))-6
z <- x*y

jpeg("version161.without_at.jpg")
foo <- levelplot(z~x*y,contour=T, cuts=5,
                 ##at=c(-10,-5,0,5,10),
                 panel=function(x,y,...){
                   panel.levelplot(x,y,  ...)
                 })
print(foo)
dev.off()

jpeg("version161.with_at.jpg")
foo <- levelplot(z~x*y,contour=T, cuts=5,
                 at=c(-10,-5,0,5,10),
                 panel=function(x,y,...){
                   panel.levelplot(x,y,  ...)
                 })
print(foo)
dev.off()



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