Comparing 2 columns of a matrix

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Gautami Golani 2019-2-23

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评论： Star Strider 2019-2-24

I want to compare 2 columns of my matrix as shown below:

For example, I have the number 4 in the first column occurring thrice. I need to compare it's corresponding values in column 2 and obtain the minimum value among them. I then need to store that value in another matrix.

Could someone suggest me a way to get this desired result.

Thanks and regards

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Answer 1

Star Strider 2019-2-23

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在 MATLAB Online 中打开

Try this (using the accumarray (link) function):

A = [randi(10, 20, 1) rand(20,1)]                               % Create Data
[A1u,~,idx] = unique(A(:,1));                                   % Unique Values & Indices
MinVals = accumarray(idx, A(:,2), [], @(x)min(x));              % Find Minimum Of Each
Result = [A1u, MinVals]                                         % Desired Result

Use your own matrix for ‘A’.

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Gautami Golani 2019-2-24

Thanks a lot for the explanation.

Star Strider 2019-2-24

As always, my pleasure.

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Answer 2

Image Analyst 2019-2-23

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You can do this easily with unique() and histogram() or histcounts(). Since you didn't include your data in a way that's easy for us to code up, I assume you'd prefer to do it yourself, so give it a try. If you run into problems, attach your data and explain the problem(s).