max value in each row with its index

hi , i have the below matrix , and i want to find the maximun value with its location(index)at each row w, so after finding the maximum value of each row then i will find maximum of maximums of these values and save it in another matirx with the same location(index) and all other values are zeros

inputmatrix=    8.0000         0    7.3398         0    8.0000
                1.6635    0.7103    3.2000    3.2000    3.2000
                3.2953    3.2000    3.2000    3.2000    3.2000
               16.0000   16.0000   16.0000   10.8963    7.6226
                8.2107    8.0000         0    5.3333    5.3333
                     0    3.2000    1.1829    3.2000    3.2000
                8.0000    4.9461         0   14.2047    8.0000
                1.4528   16.0000   16.0000   16.0000    3.3661
                8.0000    8.0000    4.0000    4.0000    4.0000
                     0    2.5510    3.0116    2.6667    2.6667
         
         
         
         
        

Answer 1

[Davide Masiello]

inputmatrix=    [8.0000         0    7.3398         0    8.0000;...
                1.6635    0.7103    3.2000    3.2000    3.2000;...
                3.2953    3.2000    3.2000    3.2000    3.2000;...
               16.0000   16.0000   16.0000   10.8963    7.6226;...
                8.2107    8.0000         0    5.3333    5.3333;...
                     0    3.2000    1.1829    3.2000    3.2000;...
                8.0000    4.9461         0   14.2047    8.0000;...
                1.4528   16.0000   16.0000   16.0000    3.3661;...
                8.0000    8.0000    4.0000    4.0000    4.0000;...
                     0    2.5510    3.0116    2.6667    2.6667];

To find the maximum of each row and their indexes

[row_max,col_idx] = max(inputmatrix,[],2)

row_max = 10×1

8.0000 3.2000 3.2953 16.0000 8.2107 3.2000 14.2047 16.0000 8.0000 3.0116

col_idx = 10×1

1 3 1 1 1 2 4 2 1 3

I am not sure what you wanna do in the next step though.

[kurdistan mohsin]

how can i find the column index of these values?

[Davide Masiello]

I realised just now that you needed the maximum for each row.

I have edited my answer so that it yield the max value for each row and the column position it can be found at.

[kurdistan mohsin]

thank you! , how can i index each value with its row and coumn index ?

[Jan]

index = sub2ind(size(inputmatrix), col_idx.', 1:5);
inputmatrix(index)  % same values as row_max

Answer 2

[Steven Lord]

Do you actually need or want the locations of the maximum element in each row or is that just a temporary step towards your ultimate goal of identifying the largest value in the whole matrix? If the latter, consider an alternate approach. Let's take some sample data.

A = randi([-10 10], 5)

A = 5×5

-4 -6 10 -5 -2 -10 -2 6 1 0 -3 -7 3 1 9 -5 -7 4 -9 -1 -5 -4 -6 7 -2

Determine the maximum value in the array (stored as value) and its linear index (stored as location.) Using the 'linear' option requires release R2019a or later.

[value, location] = max(A, [], 'all', 'linear')

value = 10

location = 11

Create an all zero array the same size as A.

B = zeros(size(A));

Set the element in B corresponding to the location of the maximum value in A to that maximum value.

B(location) = value

B = 5×5

0 0 10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

[kurdistan mohsin]

this is a great solution , but what if the location was indicated as it's row and cloumn indexing ,like in your example i want to give me the location as ; [1,3] , is it possible?