From ripley at stats.ox.ac.uk  Thu May  1 04:26:12 2008
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Thu, 1 May 2008 03:26:12 +0100 (BST)
Subject: [Rd] New version of X11, png and jpeg
In-Reply-To: <16987759.post@talk.nabble.com>
References: <alpine.LFD.1.00.0802201933470.25534@gannet.stats.ox.ac.uk>
	<16987759.post@talk.nabble.com>
Message-ID: <alpine.LFD.1.10.0805010312300.30845@gannet.stats.ox.ac.uk>

On Wed, 30 Apr 2008, Maarten Blaauw wrote:

>
> The now default Cairo results in much prettier graphs, but dense graphs such
> as plot(rnorm(1e4)) take considerably longer to plot than using
> X11(type="Xlib"). This has already been mentioned, but I was wondering if we
> users could expect Cairo speed increases in the near future?

Some.  As Michael Lawrence has already said, cairo speed is an issue and 
unlilkely to improve any time soon. And anti-aliasing takes some CPU time.

What we can do is to reduce the information passing between R and the X 
server.  I already have timer-based double buffering running (the same 
scheme as on Windows), and that helps a lot in the circumstances mentioned 
(lots of small symbols).  There are some event-loop-interface issues to 
sort out before it get committed to R-devel.

type="nbcairo" is likely to be faster in your example, but not as fast as 
the buffered device planned for 2.8.0.

The X11 server does make quite a difference -- I am running fairly decent 
Nvidia cards with the Nvidia X server module, and that has much higher 
performance than the vanilla one that Fedora ships.

In the end the reason we offer a choice of types is that there are 
different needs on the quality vs speed axis.


>> Slower under some circumstances (although on the test systems much faster
> than packages Cairo and cairoDevice).  This will be particularly true for
> X11() with a slow connection between the machine running R and the X server.
>
> Using R 2.7.0 on Ubuntu 8.04 (Pentium 4 1.70 GHz on one machine and Centrino
> Duo on another)
> -- 
> View this message in context: http://www.nabble.com/New-version-of-X11%2C-png-and-jpeg-tp15672580p16987759.html
> Sent from the R devel mailing list archive at Nabble.com.
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>

-- 
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



[Rd] New version of X11, png and jpeg
Prof Brian Ripley