Integrated S-theta, k-means clustering code added.

This commit is contained in:
Karthik 2025-04-11 03:02:00 +02:00
parent 50722c5140
commit d4c0dc3f07

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@ -80,6 +80,7 @@ end
%% Run Fourier analysis over images
fft_imgs = cell(1, nimgs);
integrated_sf = zeros(1, nimgs);
% Create VideoWriter object for movie
videoFile = VideoWriter('Single_Shot_FFT.mp4', 'MPEG-4');
@ -92,7 +93,7 @@ for k = 1 : length(od_imgs)
IMG = od_imgs{k};
[IMGFFT, IMGBIN] = computeFourierTransform(IMG);
figure(2);
figure(1);
clf
set(gcf,'Position',[500 100 1000 800])
t = tiledlayout(2, 2, 'TileSpacing', 'compact', 'Padding', 'compact'); % 1x4 grid
@ -146,8 +147,8 @@ for k = 1 : length(od_imgs)
hYLabel = ylabel('Y (pixels)', 'Interpreter', 'tex');
hTitle = title('Denoised - Masked - Binarized', 'Interpreter', 'tex');
set([hXLabel, hYLabel, hL], 'FontName', font)
set([hXLabel, hYLabel, hL], 'FontSize', 14)
set([hXLabel, hYLabel], 'FontName', font)
set([hXLabel, hYLabel], 'FontSize', 14)
set(hTitle, 'FontName', font, 'FontSize', 16, 'FontWeight', 'bold'); % Set font and size for title
ax3 = nexttile;
@ -172,11 +173,11 @@ for k = 1 : length(od_imgs)
hXLabel = xlabel('X (pixels)', 'Interpreter', 'tex');
hYLabel = ylabel('Y (pixels)', 'Interpreter', 'tex');
hTitle = title('Fourier Power Spectrum', 'Interpreter', 'tex');
set([hXLabel, hYLabel, hL, hText], 'FontName', font)
set([hXLabel, hYLabel, hL], 'FontSize', 14)
set([hXLabel, hYLabel, hText], 'FontName', font)
set([hXLabel, hYLabel], 'FontSize', 14)
set(hTitle, 'FontName', font, 'FontSize', 16, 'FontWeight', 'bold'); % Set font and size for title
% Plot the angular structure factor
% Plot the angular distribution
%{
nexttile
[theta_vals, angular_intensity] = computeAngularDistribution(zoomedIMGFFT, 10, 20, 100, 75);
@ -190,19 +191,17 @@ for k = 1 : length(od_imgs)
% Plot the angular structure factor
nexttile
[theta_vals, S_theta] = computeAngularStructureFactor(zoomedIMGFFT, 10, 20, 180, 75, 2);
integrated_sf(k) = trapz(theta_vals, S_theta);
plot(theta_vals/pi, S_theta,'Linewidth',2);
set(gca, 'FontSize', 14); % For tick labels only
hXLabel = xlabel('\theta (\pi)', 'Interpreter', 'tex');
hYLabel = ylabel('S(\theta)', 'Interpreter', 'tex');
hTitle = title('Angular Structure Factor', 'Interpreter', 'tex');
set([hXLabel, hYLabel, hL, hText], 'FontName', font)
set([hXLabel, hYLabel, hL], 'FontSize', 14)
set([hXLabel, hYLabel, hText], 'FontName', font)
set([hXLabel, hYLabel], 'FontSize', 14)
set(hTitle, 'FontName', font, 'FontSize', 16, 'FontWeight', 'bold'); % Set font and size for title
grid on
drawnow
pause(0.5)
@ -214,6 +213,94 @@ end
% Close the video file
close(videoFile);
%% Track integrated structure factor across the transition
% Assuming theta_values and integrated_sf are column vectors (or row vectors of same length)
[unique_theta, ~, idx] = unique(theta_values);
% Preallocate arrays
mean_sf = zeros(size(unique_theta));
stderr_sf = zeros(size(unique_theta));
% Loop through each unique theta and compute mean and standard error
for i = 1:length(unique_theta)
group_vals = integrated_sf(idx == i);
mean_sf(i) = mean(group_vals);
stderr_sf(i) = std(group_vals) / sqrt(length(group_vals)); % standard error = std / sqrt(N)
end
figure(2);
set(gcf,'Position',[100 100 950 750])
errorbar(unique_theta, mean_sf, stderr_sf, 'o--', ...
'LineWidth', 1.5, 'MarkerSize', 6, 'CapSize', 5);
set(gca, 'FontSize', 14); % For tick labels only
hXLabel = xlabel('\alpha (degrees)', 'Interpreter', 'tex');
hYLabel = ylabel('Integrated S(\theta)', 'Interpreter', 'tex');
hTitle = title('Change during rotation', 'Interpreter', 'tex');
set([hXLabel, hYLabel], 'FontName', font)
set([hXLabel, hYLabel], 'FontSize', 14)
set(hTitle, 'FontName', font, 'FontSize', 16, 'FontWeight', 'bold'); % Set font and size for title
grid on
%% k-means Clustering
% Reshape to column vector
X = mean_sf(:);
% Determine the number of clusters to try (you can experiment with different values here)
optimalClusters = 3; % Based on prior knowledge or experimentation
% Set the random seed for reproducibility
rng(42);
% Specify initialization method ('plus' is the default)
startMethod = 'plus'; % Options: 'uniform', 'plus', 'sample'
% Apply K-means clustering with controlled initialization
[idx, C] = kmeans(X, optimalClusters, 'Start', startMethod);
% Plot the results
figure(3);
set(gcf,'Position',[100 100 950 750])
hold on;
% Plot error bars with mean_sf and stderr_sf
errorbar(unique_theta, mean_sf, stderr_sf, 'o--', ...
'LineWidth', 1.5, 'MarkerSize', 6, 'CapSize', 5);
% Scatter plot for data points (showing clusters)
scatter(unique_theta, X, 50, idx, 'filled');
% Get the current y-axis limits
current_ylim = ylim;
% Generate colors for each cluster
colors = lines(optimalClusters); % Create distinct colors for each cluster
% Loop through each cluster and fill the regions
for i = 1:optimalClusters
% Find indices of data points that belong to the current cluster
clusterIdx = find(idx == i);
% Find the range of x-values for this cluster
x_min = unique_theta(clusterIdx(1)); % Starting x-value for the cluster
x_max = unique_theta(clusterIdx(end)); % Ending x-value for the cluster
% Fill the region corresponding to the cluster
fill([x_min, x_max, x_max, x_min], ...
[current_ylim(1), current_ylim(1), current_ylim(2), current_ylim(2)], ...
colors(i, :), 'EdgeColor', 'none', 'FaceAlpha', 0.3); % Add transparency
end
hXLabel = xlabel('\alpha (degrees)', 'Interpreter', 'tex');
hYLabel = ylabel('Integrated S(\theta)', 'Interpreter', 'tex');
hTitle = title('Regimes identified by k-means clustering', 'Interpreter', 'tex');
set([hXLabel, hYLabel], 'FontName', font)
set([hXLabel, hYLabel], 'FontSize', 14)
set(hTitle, 'FontName', font, 'FontSize', 16, 'FontWeight', 'bold'); % Set font and size for title
grid on;
hold off;
%% Helper Functions
function [IMGFFT, IMGBIN] = computeFourierTransform(I)
% computeFourierSpectrum - Computes the 2D Fourier power spectrum