How to write matrix elements with its position?

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I have a matrix A=[1 2 3; 4 5 6; 7 8 9] I want to write each entry with its row and column position e.g 111 indicates the element 1 at position first row First column , also 328 element 8 at position 3rd row and second column. so with the help of above matrix
A I want the following
111
122
133
214
225
236
317
328
339
Thanking for the anticipation.
  1 Comment
Guillaume
Guillaume on 25 Jan 2018
While it's very easy to do what you want, what is its purpose? Bearing in mind that if you don't limit A to integers [0-9] and its size to a max of 9 rows and 9 columns, then the operation is irreversible.
What would the value 1234 mean?
  • 1st row, 2nd column, value 34?
  • 12th row, 3rd column, value 4?
  • 1st row, 23rd column, value 4?

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Accepted Answer

Birdman
Birdman on 25 Jan 2018
Edited: Birdman on 25 Jan 2018
[r,c]=find(A);
val=sortrows([r c A(:)],1)
  2 Comments
Guillaume
Guillaume on 25 Jan 2018
That will fail if any value in A is 0.
[r, c] = find(true(size(A));
val = sortrows([r c A(:)],1)
would be safer.
Or:
[c, r] = ndgrid(1:size(A, 2), 1:size(A, 1));
val = [r(:), c(:), a(:)];

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More Answers (2)

Domanic
Domanic on 25 Jan 2018
Or ind2sub:
A = [1 2 3; 4 5 6; 7 8 9].';
[a,b] = ind2sub(size(A),1:numel(A));
fprintf('%d%d%d\n',[b.' a.' A(:)].')

Jan
Jan on 25 Jan 2018
What about loops?
A = [1 2 3; 4 5 6; 7 8 9];
[s1, s2] = size(A);
for i1 = 1:s1
for i2 = 1:s2
fprintf('%d%d%g\n', i1, i2, A(i1, i2));
end
end

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