If anyone got an idea or can send me to the right direction, I'd really appreciate that.
Keeping track of the Index while using "cell2mat" function
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hey guys, I have a Cell Array a and am using cell2mat function for further clustering analysis, lets say:
a = {[1 2 3; 7 8 9], [4 5 6;10 11 12; 13 14 15]};
b = cell2mat(a(:));
rng(2)
k=2;
[idx] = kmeans(b,k);
which_in_cluster = cell(k,1);
for j = 1:k
which_in_cluster{j} = find(idx == j);
end
Cluster_1 = b(which_in_cluster{1,1},:); % 1st Cluster
Cluster_2 = b(which_in_cluster{2,1},:); % 2nd Cluster
Cluster_1 =
7 8 9
10 11 12
13 14 15
Cluster_2 =
1 2 3
4 5 6
I am now looking for a way to know in which Cell number and row these clusters have originally been in a. So in this example:
Cluster_1 =
7 8 9 % This has been in Cell number 1, row index 2 of a
10 11 12 % This has been in Cell number 2, row index 2 of a
13 14 15 % This has been in Cell number 2, row index 3 of a
Any help is greatly appreciated.
Accepted Answer
Walter Roberson
on 16 Jan 2021
key = cell2mat((arrayfun(@(IDX) [repmat(IDX, size(a{IDX},1), 1), (1:size(a{IDX},1).']) , 1:numel(a), 'uniform', 0));
Now index rows of key by the cluster number to get the cell number and row number.
7 Comments
Walter Roberson
on 17 Jan 2021
F = arrayfun(@(R) f{IDX2(R,1)}(IDX2(R,2)), (1:size(IDX2,1).'))
This is probably one of the cases where it is just clearer to write a loop, and probably more efficient:
nrow = size(IDX2,1);
F = zeros(nrow,1);
for K = 1 : nrow
F(K) = f{IDX2(K,1)}(IDX2(K,2));
end
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