MATLAB: Square matrix with relationships among equal rows.

findforfor loopindexingMATLAB

I have a matrix with the following form:

    A = [ 9 9 9; 5 6 5; 9 9 9; 4 4 2; 5 6 5; 5 6 5; 4 4 4; 9 9 9]

If a particular row is equal to another, I am searching for a square matrix that contains ones, when a particular row is equal to another. Therefore if row 3 is equal to row 1, I want the elements B(1,3) and B(3,1) of a new matrix B, to be equal to 1.

Best Answer

B = ~squareform(pdist(A));

Related Solutions

MATLAB: Find the pair of the matrix

Maybe you ask for this:

   D = reshape([a.' circshift(a.',-1)], [], 2);
   D(size(a,2):size(a,2):end,:)=[];
   out =[D fliplr(D)]

MATLAB: How to modify a matrix to change the entries >=0 and multiply it by 5 AND to change the entries <0 and add 2 to those entries

Start with "If an entry in B is greater than or equal to zero": You can either run a loop over all elements of B or use "logical indexing":

% Linear indexing:
for k = 1:numel(B)
   if B(k) >= 0
     ...
   end
end

Or two indices for rows and columns:

for r = 1:size(B, 2)
  for c = 1:size(B, 1)
    if B(r, c) >= 0
       ...
    end
  end
end

Or "logical indexing":

index = (B >= 0);
disp(B(index))

Now try to use this to modify B. Use the mentioned terms to search in the documentation and in the internet.

Best Answer

Related Solutions

MATLAB: Find the pair of the matrix

MATLAB: How to modify a matrix to change the entries >=0 and multiply it by 5 AND to change the entries <0 and add 2 to those entries

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