I would support this advice. Stacked bar charts are generally not recommended
because comparisons are difficult. Having 12 groups increases the difficulty.
Best have a look at Cleveland's work before you go down your currently
intended
path. Try delving into "Elements of Graphing Data" and
"Visualizing Data".
David Scott
On Tue, 29 Jan 2008, Greg Snow wrote:
> I would question if a stacked area chart is really the best way to display
> information on 12 groups. You can put a lot of information into the plot,
> but the viewer will probably experience information overload and not be
able
> to get much useful information out of the plot. Stacked area plots rely on
> people being able to compare areas and lengths, which we don't do as
well as
> we compare positions in a graph. If your viewer is needing to go back and
> forth between the legend and the graph, then the information will be harder
> to assimilate. It may be better to use lattice/trellis graphs and plot
each
> line in its own panel (on the same scale and possibly with a light
background
> grid to make comparison easier). If there are specific comparisons that
you
> want to point out, then make a separate graph with just those comparisons
> leaving out the extra information that will just distract.
>
> If you give us a better idea of what information you are trying to convey,
we
> may be able to give you some better options for graphs to use.
>
> If you really want to go the pattern route then you may want to look at the
> discussion from october that started with:
> http://finzi.psych.upenn.edu/R/Rhelp02a/archive/111226.html and/or the
> discussion from earlier this week started by yaosheng CHEN with the subject
> "How to fill bar plot with textile rather than color".
>
> Hope this helps,
>
> --
> Gregory (Greg) L. Snow Ph.D.
> Statistical Data Center
> Intermountain Healthcare
> greg.snow at imail.org
> (801) 408-8111
>
>
>
>> -----Original Message-----
>> From: r-help-bounces at r-project.org
>> [mailto:r-help-bounces at r-project.org] On Behalf Of Markus Didion
>> Sent: Tuesday, January 29, 2008 8:42 AM
>> To: hadley wickham
>> Cc: r-help at r-project.org
>> Subject: Re: [R] B-W stacked area chart with pattern
>>
>> Thanks Hadley for your comment. I've got a minimum of 12
>> species and thus just using different greys won't do it.
>> I've tried it with two background fills, i.e. white and a
>> medium grey, and then used various angles for the shading
>> lines, even plotted it twice to obtain some sort of cross
>> shading. For good, distinguishable patterns I've been hoping
>> to be able to fill an area with different symbols.
>>
>> Markus
>>
>> hadley wickham wrote:
>>> On Jan 29, 2008 9:12 AM, Markus Didion
>> <markus.didion at env.ethz.ch> wrote:
>>>> Dear all,
>>>>
>>>> I would like to create a stacked area chart to show the
>> development
>>>> of species biomass over time. Since it is intended for
>> publication I
>>>> need to prepare in black and white. I have tried to
>> modify the "stackedPlot"
>>>> function submitted to this list by Christian Lasarczyk on
>> Tue, 16 Aug
>>>> 2005 using shading lines rather than colors to distinguish
between
>>>> the species. Unfortunately, the result was not very
>> satisfying as the
>>>> options using different angles and densities for the shading
lines
>>>> was not sufficient to clearly distinguish between species. I
would
>>>> thus like to use different pattern (or texture) for this
>> purpose. I
>>>> have searched the various help lists on graphics in R but
>> was unable
>>>> to find something appropriate.
>>>
>>> How many species do you have? Coming about with a good
>>> (distinguishable) set of patterns is a difficult task.
>> Have you tried
>>> just using different greys?
>>>
>>> Hadley
>>>
>>>
>> --
>>
>> Markus Didion
>>
>> Wald?kologie Forest Ecology
>> Inst. f. Terrestrische Oekosysteme Inst. of Terrestrial Ecosystems
>> Departement Umweltwissenschaften Dept. of Environmental Sciences
>> Eidg. Technische Hochschule Swiss Fed. Inst. of Technology
>> ETH-Zentrum CHN G78 ETH-Zentrum CHN G78
>> Universit?tstr. 22 Universitaetstr. 22
>> CH-8092 Z?rich CH-8092 Zurich
>> Schweiz Switzerland
>>
>> Tel +41 (0)44 632 5629 Fax +41 (0)44 632 1358
>> Email markus.didion at env.ethz.ch
>> homepage: http://www.fe.ethz.ch/people/didionm
>>
>> ______________________________________________
>> 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.
>>
>
> ______________________________________________
> 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.
>
_________________________________________________________________
David Scott Department of Statistics, Tamaki Campus
The University of Auckland, PB 92019
Auckland 1142, NEW ZEALAND
Phone: +64 9 373 7599 ext 86830 Fax: +64 9 373 7000
Email: d.scott at auckland.ac.nz
Graduate Officer, Department of Statistics
Director of Consulting, Department of Statistics