MATLAB: I want to find the max element in each row and position of that element in terms of row and column

i am giving the example what i have tried and what result i have got
 c=  2     3     4     5
    67    58    79    81
    91    23    56    78
[max_num,max_idx]=max(c,[],2)
 max_num =
     5
    81
    91
 max_idx =
     4
     4
     1
 >> [X,Y]=ind2sub(size(c),max_idx)
 X =
     1
     1
     1
 Y =
     2
     2
     1
i am not getting the right ans in first row max element is 5 postion will be (1,4)

Best Answer

You made a common novice user mistake: mistaking (row, column) for (x, y). Note: row is Y, not X. and column is X, not Y. ind2sub() returns [row, column], NOT [X, Y]. So you might be tempted to do:
[Y, X] = ind2sub(size(c), max_idx)
however even that is not right. Why not? Because max_idx is not the linear index over the whole matrix - it is the column number of each row. For example while max() might give [4,4,1], the linear indexes would be [4,8,9]. But that is not what you were passing in to ind2sub, you were passing in [4,4,1], so it didn't give you the expected output.
To correct the code, see the solution Star Strider gave you.
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