Re: [R] is it possible to fill with a color or transparency gradient?

From: hadley wickham <>
Date: Fri 06 Oct 2006 - 21:51:50 GMT

> I haven't been using R very long, so it's possible that I'm just
> missing something, but I haven't found anything like this in the help
> files. I've tried to poke around in graphics, grid, and ggplot,
> without any luck so far. I really like some of the functionality in
> ggplot, and it does some nice things with continuous gradients for the
> color of scatter plot points, for example, but it each individual
> point (or grob) is always one solid color as far as I can tell.

ggplot supports alpha blending provided your graphics device does too (Quartz on the mac, or pdf version 1.3 or later). Have a look at the alpha function for easily making transparent colours, as well as scgradient for specifying the colour scale.

Oh, I see you want a gradient fill on a polygon - that's a lot harder, and I can only suggest dividing your polygon up into smaller rectangles and filling those individually. That appears to be what gradient.rect does.

Hadley mailing list PLEASE do read the posting guide and provide commented, minimal, self-contained, reproducible code. Received on Sat Oct 07 07:56:45 2006

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