# Find min in matrix given specific rows and columns?

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Andrew Poissant on 1 Aug 2017
Commented: Star Strider on 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];

Star Strider on 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]
Star Strider on 2 Aug 2017
My pleasure!

Ganesh Hegade on 1 Aug 2017
You can use this.
minRow = min(min(A(r, :)));
minCol = min(min(A(:, c)));
Andrew Poissant on 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