Finding index of minimum of a subset of an array

1 次查看（过去 30 天）
ZigzS
ZigzS 2018-5-1
编辑： Matt J 2018-5-1
I want to find the index of the greater array for a subset within that array.
Example:
A=[2 3; 1 8; 2 6; 3 1;]
[row, col]=find(min(A([2 4], 2)));
This will compare the numbers 8 and 1, and I want to retrieve the index of A for the value of 1. Instead what this will output now is 2, since the subset being considered is [8 1]. What I want is for [row col] to equal [4 4], because this is the index in A where the minimum of the subset is located.
Any suggestions? Thanks,
  2 个评论
Alfonso
Alfonso 2018-5-1
I'm not sure if I have understood it correctly, you mean finding the minimum value for each row?
Matt J
Matt J 2018-5-1
What I want is for [row col] to equal [4 4], because this is the index in A where the minimum of the subset is located.
I think you mean [4,2].

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Matt J
Matt J 2018-5-1
编辑：Matt J 2018-5-1
B=A;
subset=false(size(A));
subset([2,4],2)=true;
B(~subset)=inf;
[row,col] = find(B==min(B(:))),

更多回答（1 个）

Matt J
Matt J 2018-5-1
编辑：Matt J 2018-5-1
Another way. This method is probably more efficient if you need to do this repeatedly with a large array A, but small subsets.
subset={[2,4],2}; %example
lookup=reshape(1:numel(A),size(A));
T=lookup(subset{:});
[minval,loc]=min( A(subset{:}) );
[row,col]=ind2sub(size(A), T(loc) )

类别

在 Help Center 和 File Exchange 中查找有关 Resizing and Reshaping Matrices 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by