Efficient Way to find index of max column for each row
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Les Beckham on 12 Jul 2022
Edited: Les Beckham on 12 Jul 2022
Are you wanting to find the column number of the maximum value in each row? If so, this is how you can do that:
A = magic(5) % example data
[m, idx] = max(A, , 2) % max value from each row and column number where the max value occurs
If not, please clarify what you are trying to do.
Keshav on 12 Jul 2022
Hi, Based on my understanding you have a matrix. for each row you want to find the index of maximum value. you can use the below code to do that.
x = [1 2 3; 5 3 4;10 8 9]
[mx,idx] = max(x,,2)
here idx(i) will represent the index of column with max value in ith row.
Harshit Gupta on 12 Jul 2022
Hi, I understand that you're trying to find an efficient way to find the maximum values in each row.
You can do this simply with the max() function on the matrix without using a for loop.
Here's an example:
M=[2 4 0 1;12 3 5 2;7 10 4 1;3 5 20 7]
[max_values, idx] = max(M') %row maximums
You can even get the column maximums and the maximum value of the matrix
[max_values, idx] = max(M) %col maximums
[matrix_max, idx] = max(M(:)) %matrix maximum
Hope this helps!