Thread Subject: colormap for scatter plot

Hi
I can use colormap based on Z values as
scatter3(X,Z,Y,5,Z,'filled');
However, I want to fix the range of Z between 0 and 8 and
the color for that range remains fix. Such that if the Z
data has only values between 0 and 5 then the colormap
should not re-adjust between blue and red for this range but
use maximum value for 5 as if 8 is also there in the data( I
mean red not to be assigned to 5 (max value))
I have used
scatter3(X,Z,Y,5,linspace(0,8,length(X))', 'filled');
but it linearly colormaps in Y dimension.
Thanks,

In article <fh411b$69i$1@fred.mathworks.com>,
Faisal <faisal_mufti.nospam@yahoo.com> wrote:

>I can use colormap based on Z values as
>scatter3(X,Z,Y,5,Z,'filled');
>However, I want to fix the range of Z between 0 and 8 and
>the color for that range remains fix. Such that if the Z
>data has only values between 0 and 5 then the colormap
>should not re-adjust between blue and red for this range but
>use maximum value for 5 as if 8 is also there in the data( I
>mean red not to be assigned to 5 (max value))
>I have used
>scatter3(X,Z,Y,5,linspace(0,8,length(X))', 'filled');
>but it linearly colormaps in Y dimension.

You will have to provide scatter3 with direct color values
instead of with coordinates to be interpolated.

The below is arranged to only use colors from the current colormap,
and takes into account the boundary conditions on the array sizes
and indices.

minz = 0; maxz = 8;
curcolmap = colormap;
curmapsize = size(curcolmap,1);
mapz = round(1 + (Z - minz) ./ (maxz-minz) .* (curmapsize-1));
scatter3(X, Z, Y, 5, curcolmap(mapz,:), 'filled')
--
   "I was very young in those days, but I was also rather dim."
   -- Christopher Priest

Thanks Walter, I have used 'caxis([0 8]);' and it solves my
purpose.