[R] Lattice wireframe or cloud plot with different colours by a group

[David Winsemius]

On Apr 1, 2011, at 7:46 PM, David Winsemius wrote:

>
> On Apr 1, 2011, at 6:21 PM, Pam Allen wrote:
>
>> I have a question about wireframe 3-D plots and how to apply  
>> colors.  I have
>> a large dataset of river flow (m^3/s) over time, and I have coded  
>> these
>> flows based on their height.  I would like to produce a wireframe  
>> plot that
>> colors the graph based on the flow code, i.e. I would like high  
>> flows to be
>> red, medium to be green and low flows to be blue.  Here is some  
>> sample data
>> with the basic wireframe plot:
>>
>> flow.dat=cbind.data.frame(flow=sin(2*pi/53*c(1:3000)) 
>> +1,day=as.numeric(format(as.Date(c(1:3000)),
>> format="%j")), year=as.numeric(format(as.Date(c(1:3000)),
>> format="%Y")),grp=c(rep(c("1.high","2.med","3.low"),1000)))
>
> It does not look to me that high flows are properly grouped with  
> `grp`.
>
>>
>> wireframe(flow~day*year, data=flow.dat, shade=T)
>
> wireframe(flow~day*year, data=flow.dat,  drape=TRUE,  
> col.regions=c("#FF3030","#551A8B","#43CD80"),
>          at=c(0,.6,1.3,1.8))
>
> Because of the coding at the corner and the long thin polygons you  
> have specified with your day*year splits you get slanting colors.

If you want to use grp as the color index then you need first to  
convert it to something that can be used as an index (with  
as.numeric), then use that in "[" to pull from a vector of colors:

cloud(flow~day*year,
       data=flow.dat,
       col=c("#FF3030", "#551A8B", "#43CD80")[
                        as.numeric(flow.dat$grp)],
       pch=20)

-- 
David
>
>>
>> Is there any way to specify what colours are passed to the plot?   
>> I.e.
>> wireframe(flow~day*year, data=flow.dat, shade=T, groups=grp,
>> col.group=c("#FF3030","#551A8B","#43CD80"))
>>
>> I would also be happy if I could do this with a cloud plot, but I  
>> can't get
>> the colors to plot correctly.
>> cloud(flow~day*year, data=flow.dat, shade=T, groups=grp,
>> col.group=c("#FF3030","#43CD80","#1E90FF"), pch=20)
>>
>> Any help is much appreciated!  Thank you.
>>
>> -Pam Allen
>>
>> allen_pam at hotmail.com
>>
>>
>> --
>> View this message in context: http://r.789695.n4.nabble.com/Lattice-wireframe-or-cloud-plot-with-different-colours-by-a-group-tp3421296p3421296.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
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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.
>
> David Winsemius, MD
> West Hartford, CT
>
> ______________________________________________
> 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 Winsemius, MD
West Hartford, CT