R help - Aug 2005 - color palette

Hi, I have a matrix with both positive and negative
numbers, I would like to use image() to draw a
heatmap. How can I can design a palette (or is there a
function already available) that treat negative
numbers in a blue gradient and positive numbers in a
red gradient and treat 0 as white?

Thanks

On Wed, 3 Aug 2005, array chip wrote:
> Hi, I have a matrix with both positive and negative
> numbers, I would like to use image() to draw a
> heatmap. How can I can design a palette (or is there a
> function already available) that treat negative
> numbers in a blue gradient and positive numbers in a
> red gradient and treat 0 as white?
>
?colorRampPalette

 	-thomas

'Tim.colors' in 'fields' package goes from blue to red, and
passes through
the colors cyan, yellow, and orange. Also known as Jet color-map in Matlab.
You can also easily design your own color map using 'rgb' function from
'gdDevices'.

Jarek
====================================================\======
 Jarek Tuszynski, PhD.                           o / \ 
 Science Applications International Corporation  <\__,|  
 (703) 676-4192                                   ">   \
 Jaroslaw.W.Tuszynski at saic.com                     `    \



-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of array chip
Sent: Wednesday, August 03, 2005 8:03 PM
To: r-help at stat.math.ethz.ch
Subject: [R] color palette

Hi, I have a matrix with both positive and negative numbers, I would like to
use image() to draw a heatmap. How can I can design a palette (or is there a
function already available) that treat negative numbers in a blue gradient
and positive numbers in a red gradient and treat 0 as white?

Thanks

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