Hi David,
The warning about constant “ZData” in the “contour” function suggests that at least one of your binary files may contain uniform data, which cannot produce a contour plot.
The error with “imwrite” indicates a problem with appending frames to the GIF file. The initial frame must be saved in the GIF89a format with the “Loopcount”, inf property to establish the animation. Subsequent frames should then be appended with “WriteMode”, “append”.
To automate the process of iterating over all available timesteps, you can utilize MATLAB's file listing functions to dynamically determine the number of timesteps.
Here’s how you can update your code:
clear;
clc;
close('all');
x0 = 10;
y0 = 250;
width = 1000;
height = 200;
filename = 'gif_10.gif';
h = figure('position', [x0, y0, width, height * 3]);
% Get a list of all files that match the pattern
files = dir('0_100_T_timestep_*.bin');
numFiles = length(files);
for i = 1:numFiles
% Extract the timestep number from the file name
[~, name, ~] = fileparts(files(i).name);
parts = strsplit(name, '_');
timestep = str2double(parts{end});
% Read and plot Temperature
subplot(311);
dataT = readBinaryData(['0_100_T_timestep_' num2str(timestep) '.bin']);
contourf(dataT');
colorbar;
title('Temperature');
% Read and plot Streamfunction
subplot(312);
dataS = readBinaryData(['0_100_S_timestep_' num2str(timestep) '.bin']);
contourf(dataS');
colorbar;
title('Streamfunction');
% Read and plot Vorticity
subplot(313);
dataW = readBinaryData(['0_100_W_timestep_' num2str(timestep) '.bin']);
contourf(dataW');
colorbar;
title('Vorticity');
% Capture the plot as an image
frame = getframe(h);
im = frame2im(frame);
[imind, cm] = rgb2ind(im, 256);
% Write to the GIF File
if i == 1
imwrite(imind, cm, filename, 'gif', 'Loopcount', inf);
else
imwrite(imind, cm, filename, 'gif', 'WriteMode', 'append');
end
pause(0.2); % Adjust this pause as needed
end
% Helper function to read binary data
function data = readBinaryData(filename)
fid = fopen(filename, 'r');
nx = fread(fid, 1, 'int32');
ny = fread(fid, 1, 'int32');
data = reshape(fread(fid, nx * ny, 'double'), nx, ny);
fclose(fid);
end
The above script now includes a helper function “readBinaryData” that reads the binary data files for temperature, streamfunction, and vorticity. It also automatically loops over all files that match the pattern “0_100_T_timestep_*.bin”. Adjust the pattern as necessary for your specific filenames.
For additional information about “imwrite” and “contourf” please refer to the following documentation:
