[R] image function help required

Uwe Ligges ligges at statistik.tu-dortmund.de
Fri Sep 23 19:10:57 CEST 2011



On 23.09.2011 19:03, Maxim wrote:
> Hi,
>
>
> I have a question concerning the image function and how to generate custom
> axis labels:
>
>
>
> dat<-sample(0:1,1000,replace=T)
>
> matrix(dat,ncol=5,nrow=200)->x
>
> x[order(x[,1],x[,2],x[,3],x[,4],x[,5]),]->x
>
>
> I would like to have a heatmap kind of thing like this:
>
>
>
> image(t(x),col=c(0,1),axes=F)
>
> axis(1, 1:5, c(colnames(x)))
>
>
> I only do see parts of the axis (only an "A" is drawn, position is wrong in
> addition), what is wrong?
>
>
> For a normal xy-plot this type of axis-definition obviously works
>
>
> plot(1:5, rnorm(5), axes = FALSE)
>
> axis(1, 1:5, c(colnames(x)))

You have not spewcified the x coordinates in your image() call and hence 
got the things between 0 and 1 rather than 1:5. If you want the latter, 
specify it:

image(x=1:5, z=t(x),col=c(0,1),axes=F)
axis(1, 1:5, c(colnames(x)))

Uwe Ligges


>
>
> What do I miss?
>
>
> I tried in addition lattice's levelplot (no luck yet) as well as a heatmap,
> which I find has not enough control to produce more complex pictures
> consisting of multiple plots!
>
>
> Where should I go?
>
>
> Maxim
>
> 	[[alternative HTML version deleted]]
>
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