[R] Any alternatives to draw.colorkey from lattice package?

[Felix Andrews]

You can just specify the label positions, you don't need to give
labels for every color change point:
(there is an 'at' for the color changes and a 'labels$at' for the labels)

levelplot(rnorm(100) ~ x * y, expand.grid(x = 1:10, y = 1:10),
    colorkey = list(at = seq(-3,3,length=100),
        labels = list(labels = paste(-3:3, "units"), at = -3:3)))



On 13 August 2011 19:59, Jim Lemon <jim at bitwrit.com.au> wrote:
> On 08/13/2011 04:34 AM, Mikhail Titov wrote:
>>
>> Hello!
>>
>> I’d like to have a continuous color bar on my lattice xyplot with colors
>> lets say from topo.colors such that it has ticks&  labels at few specific
>> points only.
>>
>> Right now I use do.breaks&  level.colors with somewhat large number of
>> steps. The problem is that color change point doesn’t necessary correspond
>> to the value I’d like to label. Since I have many color steps and I don’t
>> need high precision I generate labels like this
>>
>> labels<- ifelse( sapply(at,function(x) any(abs(att-x)<.03)) ,
>> sprintf("depth= %s ft", at), "")
>>
>> , where `att` has mine points of interest on color scale bar and `at`
>> corresponds to color change points used with level.colors . It is a bit
>> inconvenient as I have to adjust threshold `.03`, number of color steps so
>> that it labels only adjacent color change point with my labels.
>>
>> Q: Are there any ready to use functions that would generate some kind of
>> GRaphical OBject with continuous color scale bar/key with custom at/labels
>> such that it would work with `legend` argument of xyplot from lattice?
>>
> Hi Mikhail,
> I think that color.legend in the plotrix package will do what you are
> asking, but it is in base graphics, and may not work with lattice.
>
> Jim
>
> ______________________________________________
> 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.
>



-- 
Felix Andrews / 安福立
http://www.neurofractal.org/felix/