AFAIK, gnuplot doesn't have fine grained color control, so you might have
trouble with this. I don't know about plplot.
Here's a possibility:
# generate some data
x = rand(30,1);
y = rand(size(x));
C = rand(size(x));
# define a colormap that uses different colors for all its points
map=hsv(64);
map(1,:)=[1,1,1];
colormap(map);
# convert your x,y coordinates to image coordinates
xi = 1+round((x-min(x))/(max(x)-min(x))*399);
yi = 1+round((y-min(y))/(max(y)-min(y))*399);
# use implicit sparse->full conversion to build an image array
# use conv2 to spread spread the points out a bit (ones(5) makes
# them into a 5x5 square, but you could easily define another shape
matrix = conv2(sparse(xi,yi,C,400,400),ones(5),'same');
# if we had a proper image viewer, we could define the x and y
# axes as well:
xstep = linspace(min(x),max(x),400);
ystep = linspace(min(y),max(y),400);
imagesc(xstep,ystep,matrix);
# or if you have epsTk:
eopen("scatter.ps");
eglobpar;
eaxes([min(x),(max(x)-min(x))/10,max(x)],[min(y),(max(y)-min(y))/10,max(y)]);
eimagesc(matrix,map,'e');
eclose
eview
Paul Kienzle
address@hidden
On Wed, Dec 19, 2001 at 07:24:59PM -0500, John Day wrote:
> I have a file of 3-tuples (X,Y,C), where C is an integer 1-16, which I
want
> to scatter-plot, X by Y with C determining the color of the plotted dots.
>
> Does anyone know or have a ready-made function to do this? I don't care
> what the colors are as long as they are unique for each value of C.
> Different-shaped dots will do if we run out of colors.
>
> Thanks,
> John Day
>
>
>
> -------------------------------------------------------------
> Octave is freely available under the terms of the GNU GPL.
>
> Octave's home on the web: http://www.octave.org
> How to fund new projects: http://www.octave.org/funding.html
> Subscription information: http://www.octave.org/archive.html
> -------------------------------------------------------------
>