[R] boxplot with log="y" and values starting at 0

[John Kane]

What about "starting" the data by adding some small amount to the 0's?

Perhaps something like 
mysample <- data.frame(aa = sample(c("A","B","C"), 20, replace=TRUE), 
                 bb = sample(0:9, 20, replace=TRUE))

                 ifelse(mysample$bb==0,.1, mysample$bb)
though you may wish to make .1 much smaller.

--- On Thu, 8/20/09, Anne Skoeries <home at anne-skoeries.de> wrote:

> From: Anne Skoeries <home at anne-skoeries.de>
> Subject: [R] boxplot with log="y" and values starting at 0
> To: r-help at r-project.org
> Received: Thursday, August 20, 2009, 9:15 AM
> Hi,
> 
> I'm working with a data.frame containing values between 0
> and 22000.  
> Most of the values are actually between 0 and 50 and the
> high ones are  
> outliers.
> I want to generate a boxplot and since the outliers are
> extremely  
> high, I  need to scale the y scale logarithmically.
> Otherwise one  
> wouldn't really see the boxes of the boxplot.
> 
> boxplot(dat, log="y", ylim=c(0, max(dat)))
> 
> Trying the above doesn't work, since the y scale has to be
> positive.
> 
> But when I generate the boxplot with
> ylim=c(1, max(dat))
> it doesn't properly generate the whiskers or beginning of
> the boxes,  
> because some of the mins and first quantiles are 0.
> 
> Can anybody help and tell me how I can generate a
> logarithmic y scale  
> starting at 0?
> 
> Thanks in advance,
> --
> Anne Skoeries
> 
> 
> 
>     [[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org
> 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.
> 


      __________________________________________________________________
Looking for the perfect gift? Give the gift of Flickr! 

http://www.flickr.com/gift/