[R] heatmap color specification

[Jim Lemon]

Xiaohui wrote:
>... 
> Then, I did a heatmap for 'test' matrix. But for now, I want to specify 
> each of the cell in the heatmap according to the values of the 
> corresponding matrix elements of test.
> 
> Let's say: col<-c("red","yellow","green")
> 
> for test[1,1], the color on the map should be "red".
> 
> I have tried par('usr') and par('mar') with rect function. But this does 
> not work because the rect shift from the original map. Could any one 
> tell me how to fill the cells on the map with corresponding values? Or 
> can we get the actual coordinates of the image excluding the dendregram. 
>
Hi Xiaohui,
You may be looking for something like color2D.matplot in the plotrix 
package or "image" in the graphics package.

Jim