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Absolutely No idea how to plot my Spatial Data

6 messages · Babaorumi, Steve Lianoglou, Peter Alspach +2 more

Original
Babaorumi
# 
Hi,

I have a data set of points which are represented by 3 variables x,y,z where
x is the position of the point on the x-absciss and y on the y-absciss. Each
of my points has a value z, which I want to be displayed as follows: the
more z is high, the more the color on the map is dark.

How can I achieve this ?

Thanks for your help
Steve Lianoglou
# 
Hi,
On Thu, Mar 25, 2010 at 5:32 PM, Babaorumi <gildas.mazo.u900 at gmail.com> wrote:
How about just tweaking the alpha/transparency for each point as a
function of its value.

See this thread for inspiration:
http://thread.gmane.org/gmane.comp.lang.r.general/158649

HTH,
-steve
Peter Alspach
# 
Tena korua

Also, bear in mind that colours can be specified as grey0 - grey100;
i.e., paste('grey', round(100*z/max(z), 0), sep='').  Also, the
colorspace package is worth considering if you are not restricted to
black and white.

HTH ....


Peter Alspach
<gildas.mazo.u900 at gmail.com>
Jim Lemon
#
On 03/26/2010 08:32 AM, Babaorumi wrote:
Hi Babaorumi,
Have a look at the example for the color.scale function in the plotrix 
package.

Jim
Eik Vettorazzi
# 
Hi,

Peter Alspach schrieb:
or a lot easier using the built-in function
col=gray(z/max(z))