Re-range gray color level from 0-192 in contourf plot

Hello, seek help for re-range gray color level from 0-192 in contourf. I would like to get the color bar shows 0-192. The code as below

clear all

X = [-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150];
Y = [-150,-150,-150,-150,-150,-150,-150,-150,-150,-150,-150,-150,-150;-125,-125,-125,-125,-125,-125,-125,-125,-125,-125,-125,-125,-125;-100,-100,-100,-100,-100,-100,-100,-100,-100,-100,-100,-100,-100;-75,-75,-75,-75,-75,-75,-75,-75,-75,-75,-75,-75,-75;-50,-50,-50,-50,-50,-50,-50,-50,-50,-50,-50,-50,-50;-25,-25,-25,-25,-25,-25,-25,-25,-25,-25,-25,-25,-25;0,0,0,0,0,0,0,0,0,0,0,0,0;25,25,25,25,25,25,25,25,25,25,25,25,25;50,50,50,50,50,50,50,50,50,50,50,50,50;75,75,75,75,75,75,75,75,75,75,75,75,75;100,100,100,100,100,100,100,100,100,100,100,100,100;125,125,125,125,125,125,125,125,125,125,125,125,125;150,150,150,150,150,150,150,150,150,150,150,150,150];
r_M =[27,19,12,8,3,3,1,0,0,3,9,15,23;30,20,14,9,5,3,1,0,0,3,7,12,21;33,23,15,11,6,3,2,1,2,4,7,13,20;33,23,15,12,7,4,2,2,2,4,7,12,19;30,20,16,13,8,5,3,3,4,5,7,12,20;27,20,16,14,9,6,4,4,5,5,7,12,21;27,20,16,14,8,5,3,3,4,4,6,11,20;27,19,15,13,7,5,3,2,3,4,6,12,21;25,18,14,12,6,4,2,2,3,4,6,11,21;28,19,15,13,7,4,2,2,3,4,7,13,23;29,19,15,13,8,5,3,2,2,4,7,15,25;33,22,17,14,8,5,3,2,2,3,5,12,23;37,25,19,15,8,6,4,2,1,2,2,10,19];

figure(104)
contourf(X,Y,r_M,2560,'LineColor','none')
colormap(flipud(gray(256)));
colorbar
set(gca,'xtick',[])
set(gca,'ytick',[])

Answer 1

[Cris LaPierre]

I think you want caxis. Note this will rescale your colormap, meaning the darkest color will now be associated with 192 instead of 37. This means your figure colors will be shifted to the white end of the spectrum.

X = [-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150;-150,-125,-100,-75,-50,-25,0,25,50,75,100,125,150];
Y = [-150,-150,-150,-150,-150,-150,-150,-150,-150,-150,-150,-150,-150;-125,-125,-125,-125,-125,-125,-125,-125,-125,-125,-125,-125,-125;-100,-100,-100,-100,-100,-100,-100,-100,-100,-100,-100,-100,-100;-75,-75,-75,-75,-75,-75,-75,-75,-75,-75,-75,-75,-75;-50,-50,-50,-50,-50,-50,-50,-50,-50,-50,-50,-50,-50;-25,-25,-25,-25,-25,-25,-25,-25,-25,-25,-25,-25,-25;0,0,0,0,0,0,0,0,0,0,0,0,0;25,25,25,25,25,25,25,25,25,25,25,25,25;50,50,50,50,50,50,50,50,50,50,50,50,50;75,75,75,75,75,75,75,75,75,75,75,75,75;100,100,100,100,100,100,100,100,100,100,100,100,100;125,125,125,125,125,125,125,125,125,125,125,125,125;150,150,150,150,150,150,150,150,150,150,150,150,150];
r_M =[27,19,12,8,3,3,1,0,0,3,9,15,23;30,20,14,9,5,3,1,0,0,3,7,12,21;33,23,15,11,6,3,2,1,2,4,7,13,20;33,23,15,12,7,4,2,2,2,4,7,12,19;30,20,16,13,8,5,3,3,4,5,7,12,20;27,20,16,14,9,6,4,4,5,5,7,12,21;27,20,16,14,8,5,3,3,4,4,6,11,20;27,19,15,13,7,5,3,2,3,4,6,12,21;25,18,14,12,6,4,2,2,3,4,6,11,21;28,19,15,13,7,4,2,2,3,4,7,13,23;29,19,15,13,8,5,3,2,2,4,7,15,25;33,22,17,14,8,5,3,2,2,3,5,12,23;37,25,19,15,8,6,4,2,1,2,2,10,19];

contourf(X,Y,r_M,2560,'LineColor','none')
colormap(flipud(gray(256)));
colorbar
axis off
caxis([0 192])