[R] equal spacing of the polygons in levelplot key (lattice)

[Dennis Murphy]

OK, how about this instead?

# library('lattice')
levs <- as.vector(quantile(volcano,c(0,0.1,0.5,0.9,0.99,1)))
levq <- seq(min(levs), max(levs), length = 6)
levelplot(volcano, at = levs,
           colorkey = list(at = levq,
                                 labels = list(at = levq,
                                                   labels = levs) ))

Dennis

On Wed, Nov 16, 2011 at 10:27 AM, Andy Bunn <Andy.Bunn at wwu.edu> wrote:
>
>
>> -----Original Message-----
>> From: Dennis Murphy [mailto:djmuser at gmail.com]
>> Sent: Tuesday, November 15, 2011 8:54 PM
>> To: Andy Bunn
>> Cc: r-help at r-project.org
>> Subject: Re: [R] equal spacing of the polygons in levelplot key
>> (lattice)
>>
>> Hi:
>>
>> Does this work?
>
> Thanks Dennis.
>
> This almost works. Is there a way to make the rectangles in the key the same size? In this example five rectangles of the same area evenly arrayed? Can the key be coerced into being categorical?
>
> The data I want to work with are not spatial but it occurs to me that this is a common mapping task (e.g., in this example you might want to label these colors 'low', 'kind of low', 'medium low', etc. or map land covers or such.) I'll look at the sp or raster plotting equivalent.
>
>
>
>
>
>
>>
>> # library('lattice')
>> levs <- as.vector(quantile(volcano,c(0,0.1,0.5,0.9,0.99,1)))
>> levelplot(volcano, at = levs,
>>             colorkey = list(labels = list(at = levs,
>>                                                    labels = levs) ))
>>
>> HTH,
>> Dennis
>>
>> On Tue, Nov 15, 2011 at 1:12 PM, Andy Bunn <Andy.Bunn at wwu.edu> wrote:
>> > Given the example:
>> > R> (levs <- quantile(volcano,c(0,0.1,0.5,0.9,0.99,1)))
>> >   0%  10%  50%  90%  99% 100%
>> >   94  100  124  170  189  195
>> > R> levelplot(volcano,at=levs)
>> >
>> > How can I make the key categorical with the size of the divisions
>> equally spaced in the key? E.g., five equal size rectangles with labels
>> at levs c(100,124,170,189,195)?
>> >
>> > Apologies if this is obvious.
>> >
>> > -A
>> >
>> > R> version
>> >                _
>> >  platform       i386-pc-mingw32
>> >  arch           i386
>> >  os             mingw32
>> >  system         i386, mingw32
>> >  status
>> >  major          2
>> >  minor          14.0
>> >  year           2011
>> >  month          10
>> >  day            31
>> >  svn rev        57496
>> >  language       R
>> >  version.string R version 2.14.0 (2011-10-31)
>> >
>> > ______________________________________________
>> > 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.
>> >
>
>