Question

I am on a project thumb recognition system on matlab. I implemented Kmean Algorithm and I got results as well. Actually now I want to plot the results like here they done. I am trying but couldn’t be able to do so. I am using the following code.

load training.mat; % loaded just to get trainingData variable

labelData = zeros(200,1);
labelData(1:100,:) = 0; 
labelData(101:200,:) = 1;

k=2;

[trainCtr, traina] = kmeans(trainingData,k);

trainingResult1=[];

for i=1:k
    trainingResult1 = [trainingResult1 sum(trainCtr(1:100)==i)];
end

trainingResult2=[];

for i=1:k
    trainingResult2 = [trainingResult2 sum(trainCtr(101:200)==i)];
end

load testing.mat; % loaded just to get testingData variable

c1 = zeros(k,1054);

c1 = traina;

cluster = zeros(200,1);

for j=1:200
    testTemp = repmat(testingData(j,1:1054),k,1);
    difference = sum((c1 - testTemp).^2, 2);

    [value index] = min(difference);
    cluster(j,1) = index;
end

testingResult1 = [];

for i=1:k
    testingResult1 = [testingResult1 sum(cluster(1:100)==i)];
end

testingResult2 = [];

for i=1:k
    testingResult2 = [testingResult2 sum(cluster(101:200)==i)];
end

in above code trainingData is matrix of 200 X 1054 in which 200 are images of thumbs and 1054 are columns. actually each image is of 25 X 42. I reshaped each image in to row matrix (1 X 1050) and 4 other (some features) columns so total of 1054 columns are in each image. Similarly testingData I made it in the similar manner as I made testingData It is also the order of 200 X 1054. Now my Problem is just to plot the results as they did in here.

Answer 1

After selecting 2 features, you can just follow the example. Start a figure, use hold on, and use plot or scatter to plot the centroids and the data points. E.g.

selectedFeatures = [42,43];
plot(trainingData(trainCtr==1,selectedFeatures(1)),
     trainingData(trainCtr==1,selectedFeatures(2)),
     'r.','MarkerSize',12)

Would plot the selected feature values of the data points in cluster 1.