how can obtain min of matrix
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Matz Johansson Bergström
on 25 Jan 2015
Edited: Matz Johansson Bergström
on 26 Jan 2015
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Answers (5)
Matt J
on 26 Jan 2015
[row,col]=find(matrix==min(nonzeros(matrix)));
2 Comments
Matz Johansson Bergström
on 26 Jan 2015
Ah nonzeros , didn't even know it existed. This is the shortest and best solution and should be accepted as the answer. Good job Matt.
Matz Johansson Bergström
on 25 Jan 2015
Edited: Matz Johansson Bergström
on 25 Jan 2015
This solution is maybe a little ugly, but it works Say that A is the matrix.
tmp = A; %we will destroy elements, so we store A in tmp
tmp(tmp==0) = []; %get rid of 0-elements
val = min(min(tmp)); %find value of the smallest element
[u,v] = find(A==val, 1); %find the position
u and v is the (first) row and column of the index of the smallest element in A. The smallest element could occur several times in the matrix.
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David Young
on 25 Jan 2015
Edited: David Young
on 26 Jan 2015
Another approach:
tmp = A; % avoid destroying A
tmp(tmp == 0) = Inf; % make zero elements bigger than non-zeros
[minVal, minIndex] = min(tmp(:)); % find min value, linear index
[minRow, minCol] = ind2sub(size(A), minIndex); % convert to subscripts
or if you prefer
tmp = A;
tmp(tmp == 0) = Inf; % as above
[colminvals, colminrows] = min(tmp); % find min in each column
[minVal, minCol] = min(colminvals); % find overall min and its column
minRow = colminrows(minCol); % select row of overall min
or my personal preferred method, avoiding copying the matrix and also avoiding a repeat scan with the find operation:
nzpos = A ~= 0;
indexes = 1:numel(A);
indnz = indexes(nzpos);
[minVal, minIndnz] = min(A(nzpos));
[minRow, minCol] = ind2sub(size(A), indnz(minIndnz));
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sara
on 26 Jan 2015
Edited: sara
on 26 Jan 2015
2 Comments
Image Analyst
on 26 Jan 2015
I deleted my answer. Is there not any "Accept this answer" link for any of the others?
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