[R] using image to show RGB image data ?

hadley wickham h.wickham at gmail.com
Tue Feb 5 04:34:13 CET 2008


> I'm now using image() to show image data (in my case dumps of SOM
> weights) but would like to show RGB colour data, not just single "z"
> colour values.

You can do this fairly readily with ggplot2:

install.packages("ggplot2")
library(ggplot2)
qplot(x, y, data=mydata, fill=rgb, geom="tile") + scale_fill_identity()

(assuming that your variable containing the rgb colour is called rgb)

If your data is originally in the matrix form used by image, see the
examples on http://had.co.nz/ggplot2/geom_tile.html on how to change
to the data.frame form used by ggplot.

Hadley

-- 
http://had.co.nz/



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