# contourf with fixed colormap

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gugum gumbira on 3 May 2016
Answered: Mike Garrity on 3 May 2016
Dear all,
I have cell data contain wave high penetration for illustration purpose, I plan to create a GIF file.
It seem working well in simulate the wave penetration but the colour always changing every loop.
How to make the colormap unchanged every loop ? ?
Here I send the script that I use
V = 60:60:2340;
C = cell(size(V));
for k = 1:numel(V)
filename = sprintf('ZA00%04d.TXT', V(k));
end
figure(1)
filename = 'testnew51.gif';
C = cell2mat(C);
iwant1 = (1:708:27612) ;
iwant2 = (708:708:27612) ;
r = zeros(256, 1);
g = zeros(256, 1);
b = zeros(256, 1);
Z1=min(C(:));
Z2=max(C(:));
index999 = round((-9.9900 - Z1)/(Z2 - Z1) * 256)
r(1:index999) = linspace(0, 1, index999);
g(1:index999) = linspace(0, 1, index999);
b(1:index999) = 1;
r(index999:end) = 1;
255-index999
g(index999:end) = linspace(1, 0, 257-index999);
b(index999:end) = linspace(1, 0, 257-index999);
cmap = [r,g,b]; % jet(256);
colormap(cmap);
colorbar;
caxis([Z1, Z2]);
% [r c] = find(C==-9.9900);
%indices = find(C==-9.9900);
%C(indices)=0;
%Zlimit=[Z1 Z2];
%demcmap(Zlimit)
% colormapeditor
%[cmap]=buildcmap('bwr');
%colormap(cmap) % set colormap disini
%caxis ([-10 10])
for n = 1:length(iwant1) % looping sepanjang kolom1
contourf(flipud(flipud(flipud(C(:,iwant1(n):iwant2(n)))))) ; % Plot contour sesuai kolom
drawnow % update gambar per frame
frame = getframe(1); % mendapatkan gambar setiap frame
%F = getframe(gcf);
%image(F.cdata)
im = frame2im(frame); % convert frame ke image
[imind,cm] = rgb2ind(im,256); % convert RGB image ke indexceed image
if n == 1;
imwrite(imind,cm,filename,'gif', 'Loopcount',inf); % image ke file grafik
else
imwrite(imind,cm,filename,'gif','WriteMode','append');
end
end

Mike Garrity on 3 May 2016
Try uncommenting the call to caxis and moving it after the call to contourf. It needs to be after the call to contourf because that (like most plotting functions) resets the CLim of the axes.