From nikko at hailmail.net  Wed Dec  2 17:57:32 2009
From: nikko at hailmail.net (Nicholas Lewin-Koh)
Date: Wed, 02 Dec 2009 08:57:32 -0800
Subject: [Rd] raster support in graphics devices
In-Reply-To: <mailman.27.1259751606.22148.r-devel@r-project.org>
References: <mailman.27.1259751606.22148.r-devel@r-project.org>
Message-ID: <1259773052.5674.1348091557@webmail.messagingengine.com>

Hi Charlotte,
I think I would have to respectfully disagree with you on many points.
While we all sigh when we see heatmaps used as data to explain
everything,
they do have their uses. But beyond heat maps, the nature and demands of
modern
statistical graphics has changed. Plotting huge data sets requires
generalization,
eg binning. Plotting binned data is more efficient in raster form.
Further, 
information visualization often requires blending raster images with
vector graphics.
There is as great many more examples where efficient use of raster
graphics in an R
device is a step forward. 

With regards to the X11 device I think we can safely say that it is a
legacy device. We
have all hit up on the limitations of what can be done on the x11
device, and hence
the slew of new devices that have been introduced to fill the void.
Cairo is slower,
but I think we can safely assume that speed will improve as
optimizations are added and
Moores law kicks in. 

Paul has added many interesting 2d vector graphics tools. Look at the
svn commits
over the years, xsplines, line joining (mitre), fonts, plotmath, ...
There is plenty of work on refining 2d graphics. 3d graphics and
interactive
graphics are also important. R is a flexible tool for prototyping new
graphical methods.
Why shoot ourselves in the foot?

Anyway, nough said.

Nicholas

> ------------------------------
> 
> Message: 9
> Date: Wed, 2 Dec 2009 12:36:18 +1200
> From: Charlotte Maia <maiagx at gmail.com>
> Subject: Re: [Rd] raster support in graphics devices
> To: Simon Urbanek <simon.urbanek at r-project.org>
> Cc: r-devel at r-project.org
> Message-ID:
> 	<b7bfe54e0912011636n4cb4636i587caab5bc5e6b68 at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> On 12/2/09, Simon Urbanek <simon.urbanek at r-project.org> wrote:
> > Charlotte,
> >
> >
> > I would like to point out that implicitly you have been already using raster
> > graphics all the time in very inefficient form in heatmaps etc. The point
> > here is not really about added functionality for the user but efficiency,
> > because now we can finally use efficient encoding of heatmaps, matrix
> > visualizations, overlay data over satellite images etc. Although all this
> > was always possible in R, it was very inefficient and caused unwanted side
> > effects (see the constant anti-aliasing discussions).
> >
> > Cheers,
> > Simon
> 
> I might be unpopular for saying this, heatmaps are horrible things.
> The first time I created a heatmap, I thought this is pretty, I've
> since learnt better.
> 
> If I wasn't unpopular for saying that, this will certainly make me
> unpopular, what is with that image at the top of JSS? There is bad
> typesetting, and then there is bad typesetting...
> 
> I think many users are getting caught up in creating pretty images,
> and the impression I'm getting is that various software (not just R)
> is making this easier.
> Whenever I'm reading an article and I see a heatmap, I say a few curse
> words and then just settle for reading the abstract, and maybe the
> first page of the introduction, if I've had a good day...
> 
> There are still substantial problems with R's vector graphics,
> creating curves and circles for example. On evince, my plots just look
> like a bunch of "q"s (not sure whether it's evince's fault or R's
> fault). Plus including figures in sweave is relatively difficult in my
> opinion.
> 
> Regarding Martins comments on changing the graphics device, I have
> noticed some errors in doing so, hence have been (reluctantly)
> sticking to cairo. What that saying, if you can't beat them, joint
> them... or something like that...
> 
> Then there's all those people (have no idea if this is correct or not)
> that say creating plots in SAS and Matlab is faster than R.
> 
> Overall, I think there is substantial room for improvement both in the
> use and implementation of vector graphics, especially static 2D vector
> graphics, however trends for implementing  interactive graphics, 3d
> graphics, and raster images seem to be getting too much precedence.
> 
> In regards to Simon's comments, if we are going to focus on
> efficiency, shouldn't we make the useful things efficient first, and
> not gett too distracted.
> 
> I don't know anything about matrix visualisation, however I'm
> sceptical that it is a good idea to take a giant matrix, and map one
> element to one pixel, say with colour indexing (essentially just
> another heatmap).
> 
> Noting my opinions here are in regards to the entire R community
> (really the entire statistical community), not just the original post.
> 
> 
> regards
> -- 
> Charlotte Maia
> http://sites.google.com/site/maiagx/home
> 
> 
>



[Rd] raster support in graphics devices
Nicholas Lewin-Koh