[R] Point size problem

[Prof Brian Ripley]

On Thu, 26 Jun 2008, Marcin Kozak wrote:

> Hi all,
>
> I have a simple question and couldn't find any post on this. When
> plotting simple scatterplots (other plots as well), e.g.,
>
> x<-rnorm(30, 10, 1)
> y<-rnorm(30, 10, 1)
> plot(x, y, pch = 15, cex = 1),
>
> the points, even those close to each other, may have visibly different
> sizes. Do you know what's going on with that?

No, because you haven't followed the posting guide and told us your OS, R 
version and what graphics device this is.

This may be an artefact of rasterization in the device, since you are 
plotting squares with numeric (not integer) coordinates, and these need to 
be mapped to pixels on a screen device.  So for example the interval (3.7, 
6.0) might light up 3 pixels, and (3.4, 5.7) might light up 4.

>
> Thanks in advance,
> Marcin
>
> ______________________________________________
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595