Re: [R] overlapping labels

From: Gavin Simpson <gavin.simpson_at_ucl.ac.uk>
Date: Mon, 03 Dec 2007 19:44:49 +0000

Duncan Murdoch wrote:

> On 12/3/2007 12:21 PM, Biscarini, Filippo wrote:

>> Good evening,
>>
>> I am trying to add labels to the point of a simple plot, using the
>> text() function; the problem is that sometimes, if two points are too
>> close to each other, labels overlap and are no longer readable.
>> I was wondering whether there are options that I can use to prevent this
>> overlapping (by, for example, placing labels alternatively above and
>> below the plotted curve), or whether I should use another set of
>> graphical functions (grid or lattice packages).
>> Does anybody have suggestions?
> 
> I don't think there are any functions to automatically avoid overlaps, 
> but it is not hard to manually move some of the labels.  

The OP might like to take a look at the orditorp function in package vegan, which is designed to add information from complex ecological data sets with many species to ordinations. It works out if a label can be placed and if not draws a point. The OP would have to modify it to try another place to plot, but that might be a basis from which to work.

Of course, if this is a one-off project Duncan's solution is more than adequate.

G

For example,

> you could alternate labels above and below with code like this:
> 
>  > x <- 1:10
>  > y <- rep(0, 10)
>  > plot(x,y)
>  > text(x, y, rep("label", 10), pos=rep(c(1,3), 5))
> 
> because the pos parameter can be specified separately for each observation.
> 
> Duncan Murdoch
> 

>>
>> Thank you,
>>
>> Filippo Biscarini
>>
>> PS: These are the lines of codes that I have been using to generate the
>> plot.
>>
>> plot(
>> prova$x,
>> prova$y,
>> type="b",
>> mar=c(0.5,0.5,0.5,0.5),
>> xlab="basepairs",
>> ylab=""
>> );
>>
>> text(
>> prova$x,
>> prova$y,
>> prova$lab,
>> pos=3,
>> offset=2,
>> cex=0.5
>> );
> 
> ______________________________________________
> 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.


-- 
%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
  Dr. Gavin Simpson             [t] +44 (0)20 7679 0522
  ECRC, UCL Geography,          [f] +44 (0)20 7679 0565
  Pearson Building,             [e] gavin.simpsonATNOSPAMucl.ac.uk
  Gower Street, London          [w] http://www.ucl.ac.uk/~ucfagls/
  UK. WC1E 6BT.                 [w] http://www.freshwaters.org.uk
%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%

______________________________________________
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.
Received on Mon 03 Dec 2007 - 19:54:52 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Mon 03 Dec 2007 - 20:30:17 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.