find the multiple max values

45 次查看（过去 30 天）

显示更早的评论

chung yen chang 2020-6-16

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/549117-find-the-multiple-max-values

评论： madhan ravi 2020-6-18

采纳的回答： madhan ravi

I have a matrix

8 23 44 19

44 5 62 1

7 6 12 33

6 55 24 8

and I want to find 3 largest values(reserve duplicate matches),and then make the other be 0

just like

0 0 44 0

44 0 62 0

0 0 0 0

0 55 0 0

I have read some book ，but I still have no idea

help me plz

3 个评论
显示 1更早的评论隐藏 1更早的评论

chung yen chang 2020-6-18

q=[6 7 3 2
5 3 6 4
7 7 5 3
7 9 10 5]
 [x,y]=sort(q(:))
 q(y(1:end-3))=0

in this case matrix can't preserve max three values

chung yen chang 2020-6-18

the answer would be

q =

0 0 0 0

0 7 0 0

0 9 10 0

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

madhan ravi 2020-6-16

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/549117-find-the-multiple-max-values#answer_451899

编辑：madhan ravi 2020-6-16

MaX = maxk(matrix(:), 3);
Wanted = ismember(matrix, MaX) .* matrix
% for older versions
m = sort(matrix(:),'descend');
Wanted = ismember(matrix, m(1:3)) .* matrix

11 个评论
显示 9更早的评论隐藏 9更早的评论

madhan ravi 2020-6-18

In the command window just call the function

Matrix = randi(10,4); % an example
Wanted = Mx(Matrix)
% function definition
function Wanted = Mx(matrix) % save it as a separate file called Mx.m
... the Code
end

Stephen23 2020-6-18

Note that this answer does not "find 3 largest values" as the question requested:

>> matrix = [4,4,4;4,4,4;3,2,1]
matrix =
   4   4   4
   4   4   4
   3   2   1
>> m = sort(matrix(:),'descend');
>> Wanted = ismember(matrix, m(1:3)) .* matrix
Wanted =
   4   4   4
   4   4   4
   0   0   0

The problem is caused by the use of sort. See my answer for the correct solution.

请先登录，再进行评论。

更多回答（1 个）

Stephen23 2020-6-16

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/549117-find-the-multiple-max-values#answer_451923

Where M is your matrix:

>> U = unique(M(:));
>> X = ismember(M,U(end-2:end));
>> M(~X) = 0
M =
    0    0   44    0
   44    0   62    0
    0    0    0    0
    0   55    0    0

3 个评论
显示 1更早的评论隐藏 1更早的评论

Stephen23 2020-6-18

编辑：Stephen23 2020-6-18

"Thanks, bro this answer can work very well"

Note my answer actually gives the output that you asked for (unlike the answer that you accepted):

>> M = [4,4,4;4,4,4;3,2,1]
M =
   4   4   4
   4   4   4
   3   2   1
>> U = unique(M(:));
>> X = ismember(M,U(end-2:end));
>> M(~X) = 0
M =
   4   4   4
   4   4   4
   3   2   0