Find a Maximum in a Matrix

Hello all,

I am trying to find a maximum in a 484x1800 matrix. Particularly i´d need the index of the maximum of each row.

The result should be a 484x1 vector or 1x484 with the index of each maximum on each place of the vector.

I tried a few things with find and max and max(abs.... but it seems that the subscription in a matrix does not fit with these functions.

Please help,

Thanks,

Answer 1

[Thomas]

There probably is a more elegant solution but this should work

a=rand(40,10);   %some random 40x10 data
for i=1:length(a)
    [~,c(i),~]=find(a(i,:)==max(a(i,:)));
end

values=max(a,[],2);

% this is the largest value in each row and its position in the row
output=[c' values]

Answer 2

[Sean de Wolski]

X = rand(484,1800);
[maxval,idxmax] = max(X,[],2)

and for more info

doc max

[Thomas]

+1 I forgot that max gives the value and index.. :)