How Detect duplicate value in each column and replace one value with zero?

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For example A=[ 5 3 2 5 1 3 1 1 2 2; 5 8 6 6 1 4 4 2 3 3; 7 9 9 7 4 8 10 6 4 7; 8 10 10 9 9 8 10 6 5 7] In first column 5 duplicate and in five column 1 duplicate I want replace one of duplicated values with 0 i tried this but not give correct answer diffrent=find(diff(A(1:4,:))==0); A(diffrent)=zeros(size(diffrent));

Accepted Answer

Andrei Bobrov
Andrei Bobrov on 31 Mar 2017
Edited: Andrei Bobrov on 31 Mar 2017
Aout = [true(1,size(A,2));diff(A)~=0].*A;
or for matrix not sorted by columns:
[m,n] = size(A);
[A1,ii] = sort(A);
[~,i1] = sort(ii);
A2 = [true(1,n);diff(A1)~=0].*A1;
Aout = A2(sub2ind([m,n],i1,repmat(0:n-1,m,1));
  3 Comments
safaa
safaa on 1 Apr 2017
is there way to make first duplicate element 0 instead of second element ?
Andrei Bobrov
Andrei Bobrov on 3 Apr 2017
A1 = [5 3 9 7 1 4 10 2 3 7
8 9 10 6 1 8 10 6 5 3
7 8 2 9 4 8 1 2 2 7
5 10 6 7 1 3 4 6 4 7];
[A2,i0] = sort(A1);
A2 = [diff(A2) ~= 0;true(1,n)].*A2;
[~,i1] = sort(i0);
Aout = A2(m*(0:n-1)+i1);

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