R devel - Apr 2009 - reversing xlim, ylim in smoothScatter

Hello,

I have found that in smoothScatter it is not possible to reverse the axes
plotted (R version 2.9.0) .   It appears that this arises from the hard coding
of xlim and ylim in smoothscatter.R in the lines :

x <- x[ xlim[1] <= x[,1] & x[,1] <=xlim[2], ]   (line  number 25)

and 

x <- x[ ylim[1] <= x[,2] & x[,2] <= ylim[2], ]  (line number 31)

This results in a x being NA if ylim[1] > ylim[2] which results in an error
on executing
 map <- grDevices:::.smoothScatterCalcDensity(x, nbin, bandwidth)

To counter this problem, I replaced the above two lines by :
x <-x [min(xlim) <= x[,1] & x[,1] <= max(xlim), ]

and 
x <- x[min(ylim) <= x[,2] & x[,2] <= max(ylim), ]

and now smoothscatter reverses axes properly if xlim and/or ylim are provided
with reversed ranges.  

I am wondering if this would break something somewhere else or if there is a
better way to reverse the axes.     (I am a newbie in R programming although I
have been using R for some astronomical plots and computations etc...)

Thanks in advance for your comments!  
Shashi
--


 

Shashikiran Ganesh 

http://www.prl.res.in/~shashi 

http://cosmicdiary.org/blogs/shashikiran_ganesh/
Registered linux user number: 39542 (http://counter.li.org)


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>>>>> "SG" == Shashikiran Ganesh <shashikiran_ganesh
at yahoo.co.in>
>>>>>     on Wed, 22 Apr 2009 17:16:09 +0530 (IST) writes:
    SG> Hello,
    SG> I have found that in smoothScatter it is not possible to reverse the
axes plotted (R version 2.9.0) .?? It appears that this arises from the hard
coding of xlim and ylim in smoothscatter.R in the lines :

    SG> x <- x[ xlim[1] <= x[,1] & x[,1] <=xlim[2], ]?? (line?
number 25)

    SG> and 

    SG> x <- x[ ylim[1] <= x[,2] & x[,2] <= ylim[2], ]? (line
number 31)

    SG> This results in a x being NA if ylim[1] > ylim[2] which results in
an error on executing
    SG> ?map <- grDevices:::.smoothScatterCalcDensity(x, nbin, bandwidth)

    SG> To counter this problem, I replaced the above two lines by :
    SG> x <-x [min(xlim) <= x[,1] & x[,1] <= max(xlim), ]

    SG> and 
    SG> x <- x[min(ylim) <= x[,2] & x[,2] <= max(ylim), ]

    SG> and now smoothscatter reverses axes properly if xlim and/or ylim are
provided with reversed ranges.??

    SG> I am wondering if this would break something somewhere else or if
there is a better way to reverse the axes. ? ? (I am a newbie in R programming
although I have been using R for some astronomical plots and computations
etc...)

No, I don't think your proposed change could create problems,
but to the contrary, I'd declare it as a simple bug fix,
so it will be part of the next versions of R,
thank you very much!

Martin Maechler, ETH Zurich

    SG> Thanks in advance for your comments!? 
    SG> Shashi
    SG> --
    SG> Shashikiran Ganesh 

    SG> http://www.prl.res.in/~shashi 

    SG> http://cosmicdiary.org/blogs/shashikiran_ganesh/
    SG> Registered linux user number: 39542 (http://counter.li.org)