[R] pch="." plots much faster

[Henrik Bengtsson]

FYI,

there is also smoothScatter() in the 'geneplotter' package (part of
the Bioconductor.org project).

/Henrik

On Tue, May 13, 2008 at 5:08 AM, Prof Brian Ripley
<ripley at stats.ox.ac.uk> wrote:
> On Tue, 13 May 2008, Charles Plessy wrote:
>
>
> > Dear list,
> >
> > I realised by chance when analysing a 1521862 × 8 matrix that plotting
> > was much faster when using "." as the argument of `pch'.
> >
>
>  Why is that surprising?  Drawing a small square is rather easy compared to
> a circle, say.
>
>
>
> > I was just wondering if there were other ways to get this speed
> improvement: it is otherwise quite difficult to explore such big matrices,
> especially given that X11 redraws the plot whenever its window is
> covered/uncovered by another window, or when I switch virtual desktops.
> >
>
>  That is a function of your X setup.  R does ask for backing store to be
> used, and so it seeems your setup is not doing so. Also, the type="cairo" in
> X11() will repaint from a backing pixmap.
>
>  You might want to contemplate better ways to visualize 1.5m points.  It is
> not clear what plot you are actually doing, but a density plot is likely to
> be more informative (especially a 2D pairs plot of densities), or a hexbin
> plot (from the BioC package or that name) or ....
>
>
>
>
> >
> > Best regards,
> >
> > --
> > Charles Plessy,
> > Wakō, Saitama, Japan
> >
> > ______________________________________________
> > 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.
> >
> >
>
>  --
>  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
> ______________________________________________
>  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.
>
>