[BioC] color scheme heatmap.2

[Sean Davis]

Roel Verhaak wrote:
> Dear list,
>
> I am generating genes vs samples expression heatmaps using the heatmap.2 
> function from the gplots library. The heatmap data is centered around 
> zero and varies from approximately -6 to 6.
>
> Like the heatmap function, a color scheme needs to be specified, for 
> which I have used greenred(75) so far.  The most extreme green and red 
> colors are now assigned to the most extreme values; it is also possible 
> to define a color scheme that assigns the most extreme colors to not the 
> most extreme values, for instance -3 and 3 in my case?
>   
Look at the breaks argument:

heatmap.2(....,breaks=seq(-3,3,-0.1),col=greenred(59))

Sean