# Find min in matrix given specific rows and columns?

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Andrew Poissant am 1 Aug. 2017
Kommentiert: Star Strider am 2 Aug. 2017
I have a matrix, A, and I want to find the minimum value given specified row and column vectors, r and c. I also want to return the col and row of that minimum value in A. Any idea how to find the min? Given A, r, and c, the answer for this scenario should be a min value of 1 because it is in row 1, col 1, which is a part of the r and c vectors.
A = [1 12 23 19 1 13;
2 3 13 34 5 75;
5 22 45 5 1 94;
4 5 68 2 5 17;
2 4 34 11 13 92];
r = [1 3 4];
c = [1 2 3];
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### Akzeptierte Antwort

Star Strider am 1 Aug. 2017
One approach:
idx = sub2ind(size(A), r', c'); % Define ‘Eligible’ Elements As Linear Index Vector
[minval,minidx] = min(A(:)); % Minimum & Location (Linear Index)
[rmin,cmin] = ind2sub(size(A),intersect(minidx,idx)); % Recover Row, Column Indices Of ‘Eligible’ Minimum
fprintf('\nMinimum of A = %d, at [%2d,%2d]\n', minval, rmin, cmin)
Minimum of A = 1, at [ 1, 1]
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Andrew Poissant am 2 Aug. 2017
I changed the value of 1 in cell [1,1] to 11 and it gave the empty cell. However, your edit is working perfectly. Thanks for the help!
Star Strider am 2 Aug. 2017
My pleasure!

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### Weitere Antworten (1)

Ganesh Hegade am 1 Aug. 2017
You can use this.
minRow = min(min(A(r, :)));
minCol = min(min(A(:, c)));
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Andrew Poissant am 2 Aug. 2017
I am confused by this response. This finds the minimum for the row and column separately or am I not understanding what you are doing? I need something that will take the rows and columns specified in the r and c vectors, respectively, and search those defined rows and columns for the minimum value. How would I use this to obtain my answer? Thanks

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