how can obtain min of matrix

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sara 2015-1-25

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编辑： David Young 2015-1-26

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Matz Johansson Bergström 2015-1-25

编辑：Matz Johansson Bergström 2015-1-26

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Answer 1

Matt J 2015-1-26

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在 MATLAB Online 中打开

[row,col]=find(matrix==min(nonzeros(matrix)));

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sara 2015-1-26

thanks Matt

Matz Johansson Bergström 2015-1-26

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.

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Answer 2

Matz Johansson Bergström 2015-1-25

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编辑：Matz Johansson Bergström 2015-1-25

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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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Answer 3

David Young 2015-1-25

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编辑：David Young 2015-1-26

在 MATLAB Online 中打开

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));