How to delete duplicate values in a column

Matrix A is as follows:

A = [10023  10024  10025  10026  10027
1  1  1  1  1
1  1  1  1  1
1  1  2  1  1
2  3  2  5  1
2  3  2  5  2
4  3  4  5  1
4  3  4  6  1
1  3  4  6  1
1  1  1  1  1];

I want to remove the duplicate number in each column and produce the new matrix B like following:

B = [10023  10024  10025  10026  10027
1  1  1  1  1
2  3  2  5  2
4  1  4  6  1
1  0  1  1  0];

% The zero are added to ID numbers 10024 & 10027 in order to keep the consistenty of matrix B dimension.

Answer 1

[Image Analyst]

This works:

A = [10023  10024  10025  10026  10027
  1  1  1  1  1
  1  1  1  1  1
  1  1  2  1  1
  2  3  2  5  1
  2  3  2  5  2
  4  3  4  5  1
  4  3  4  6  1
  1  3  4  6  1
  1  1  1  1  1]

B = zeros(size(A));
for col = 1 : size(A, 2)
  thisCol = A(:, col);
  thisCol(diff(thisCol) == 0) = []; % Remove repeats.
  B(1:length(thisCol), col) = thisCol;
end
% Trim off all zero rows
lastRow = find(all(B==0, 2), 1, 'first')-1;
B = B(1:lastRow, :)

[Zhan]

Great!

Can you now categorize IDs based on the out of B matrix? For example:

T1 = [10023  10025
1  1
2  2
4  4
1  1
];

T2 = [10024
1
3
1
0];

T3 = [10026
1
5
6
1];

T4 = [10027
1
2
1
0];

% All IDs with sequence 1241 are added to the matrix T1 and so on...

[Image Analyst]

Transpose B and pass it into unique() with the 'sortrows' option. Then use ismember() to find out where those rows occur in B and extract them. See if you can do it yourself.

[Zhan]

Thanks for guiding me. I don't know how to set up ismember() function in order to extract them. Can you pls help

[Image Analyst]

Try

[inA, inB] = ismember(A, B);

and see what inA and inB are. Try swapping A and B. I'm sure you can figure it out.

[Zhan]

I couldn't make it. Can you help with code ?

[Image Analyst]

OK, then why not simply do this

T1 = B(:, [1,3]);
T2 = B(:, 2);
T2 = B(:, 4);
T2 = B(:, 5);

[Zhan]

But if matrix A has over 100 columns? Can you please help me on the second part of my question?

[Image Analyst]

Well what did you try? Did you get anything like this:

A = [10023  10024  10025  10026  10027
  1  1  1  1  1
  1  1  1  1  1
  1  1  2  1  1
  2  3  2  5  1
  2  3  2  5  2
  4  3  4  5  1
  4  3  4  6  1
  1  3  4  6  1
  1  1  1  1  1]

B = zeros(size(A));
for col = 1 : size(A, 2)
  thisCol = A(:, col);
  thisCol(diff(thisCol) == 0) = []; % Remove repeats.
  B(1:length(thisCol), col) = thisCol;
end
% Trim off all zero rows
lastRow = find(all(B==0, 2), 1, 'first')-1;
B = B(1:lastRow, :)'
bRight = B(:, 2 : end)
B2 = unique(bRight, 'rows')
% Go down these rows finding out all the rows that have the row
for row = 1 : size(B2, 1)
  thisRow = B2(row, :)
  [ia, ib] = ismember(bRight, thisRow, 'rows')
  extractedRows = B(ia, :)';
  T{row} = extractedRows;
end
celldisp(T)

And you'll see:

T =
  1×4 cell array
    [5×1 double]    [5×2 double]    [5×1 double]    [5×1 double]
T{1} =
       10027
           1
           2
           1
           0
T{2} =
       10023       10025
           1           1
           2           2
           4           4
           1           1
T{3} =
       10024
           1
           3
           1
           0
T{4} =
       10026
           1
           5
           6
           1