A command like "unique" for matrices?

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Amy Hs
Amy Hs on 23 Apr 2019
Commented: Amy Hs on 23 Apr 2019
Hi guys,
Is there any command like "unique" for matrices?
I have a major matrice (mother) , and that involve few minor matrices, some of are repeated randomly
i'm looking for a command for delete repeated ones and do something like unique ,
anybody knows how?
  3 Comments
Andrei Bobrov
Andrei Bobrov on 23 Apr 2019
Please post an example of your matrix and what you want to receive.
Amy Hs
Amy Hs on 23 Apr 2019
thanks for your reply
see,
we have 3 matrices,
A=[1;2;3] ; B=[1;2;3] ; C=[4;5;6];
all of them are in another matrice (call it R)
R={A;B;C}
as you see A & B 's first column are the same,
i want to delete one of them (A or B) and the result must be like below:
R={A;C}

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Accepted Answer

Stephen23
Stephen23 on 23 Apr 2019
Edited: Stephen23 on 23 Apr 2019
A general solution that does not concatenate the data and works for any size arrays:
% Fake data:
A = [1;2;3];
B = [1;2;3];
C = [4;5;6];
R = {A;B;C}
% Method:
N = numel(R);
X = false(1,N);
for ii=2:N
Y=false;
for jj=1:ii-1
Y = Y || isequal(R{ii},R{jj});
end
X(ii) = Y;
end
R(X) = []

More Answers (1)

Andrei Bobrov
Andrei Bobrov on 23 Apr 2019
A=[1;2;3];
C=[4;5;6];
M = [repmat(A,2,1);C];
out = reshape(unique(reshape(M,3,[])','rows','stable')',[],1);

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