Info
此问题已关闭。 请重新打开它进行编辑或回答。
Identifying and modifying the maximum in a matrix.
1 次查看(过去 30 天)
显示 更早的评论
I have a 100 by 200 matrix of random numbers. I want to identify the max number in each row and set it to 1, while setting everything else equal to 0.
Im able to identify the max, but currently unable to set up the for loop to modify the matrix.
Is anyone able to help?
0 个评论
回答(2 个)
KSSV
2018-6-6
A = rand(100,200) ;
iwant = zeros(size(A)) ;
[m,n] = size(A) ;
for i = 1:m
[val,idx] = max(A(i,:)) ;
iwant(i,idx) = 1 ;
end
0 个评论
Stephen23
2018-6-6
编辑:Stephen23
2018-6-6
This is MATLAB, so no loops are required for this task. It is easy in just one line:
>> M = randi(9,10,20) % fake data
M =
3 6 7 2 2 2 6 2 2 5 6 6 6 7 2 4 7 4 4 4
9 1 5 7 8 5 7 4 5 9 8 6 6 1 6 5 7 2 5 4
4 1 1 7 3 7 6 6 4 7 2 3 3 3 9 8 1 5 1 8
5 2 1 6 9 9 3 6 4 7 3 6 7 2 8 3 4 9 3 3
7 2 2 8 1 6 9 4 9 1 5 4 2 2 8 7 8 2 7 9
2 8 5 9 6 5 7 5 1 8 5 2 1 2 2 1 3 5 9 9
2 2 9 6 9 6 5 6 3 3 2 8 6 8 1 1 1 1 9 9
6 6 2 8 4 8 8 7 6 9 1 4 4 9 4 3 6 9 7 2
2 9 2 2 4 7 8 9 2 9 6 7 1 7 5 3 7 4 5 8
6 4 8 6 9 7 2 9 7 3 7 3 3 1 7 9 3 8 1 6
>> M(:) = bsxfun(@eq,M,max(M,[],2))
M =
0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 0
1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 1 0 0
0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 1
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1
0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1
0 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 1 0 0
0 1 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0
0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0
This marks every instance of the maximum values in the row, If you only want to mark the first instance of the maximum value in the row, then this is also easy:
>> M(:) = M & cumsum(M,2)==1
M =
0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0
0 个评论
此问题已关闭。
另请参阅
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!