different outputs for same input in every run

Question

Hamid 2022-8-4

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1773605-different-outputs-for-same-input-in-every-run

评论： Hamid 2022-8-4

采纳的回答： KSSV

data.mat

在 MATLAB Online 中打开

Dear all,

I am using fitcknn function and I expect a 8*2 matrix to be the output (detected varialble). But sometime the output is correct and other times not. I used fixed rand number seed and clear all variables before every run but it does not work.

Any idea what is the problem of my code? Many thanks in advance.

clear all;
data = load('data.mat').data;
%%%%%%%%%
find_kmeans=kmeans(data(:,1),2);
data_2=table(data(:,1),find_kmeans(:));
data_2.Properties.VariableNames = ["counts", "detect"];
Mdl=fitcknn(data_2,'detect');
Mdl.NumNeighbors=1;
test_data=data(:,1);
pred=predict(Mdl,test_data);
wanted_points=(find (pred==2));
wanted_points_cnts= data(wanted_points,1);
detected=table(wanted_points(:),wanted_points_cnts(:));
scatter(wanted_points,wanted_points_cnts)

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Walter Roberson 2022-8-4

I do not see a fixed random number seed?

Reminder: kmeans() does random initialization, so you would need to set the seed before the kmeans call.

Hamid 2022-8-4

@Walter Roberson Many thanks for the useful comment. I removed it here and maybe the line I wrote my randon seed was wrong.

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Answer 1

KSSV 2022-8-4

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1773605-different-outputs-for-same-input-in-every-run#answer_1020885

在 MATLAB Online 中打开

    
%%%%%%%%%
rng(1)
find_kmeans=kmeans(data(:,1),2);
data_2=table(data(:,1),find_kmeans(:));
data_2.Properties.VariableNames = ["counts", "detect"];
Mdl=fitcknn(data_2,'detect');
Mdl.NumNeighbors=1;
test_data=data(:,1);
pred=predict(Mdl,test_data);
wanted_points=(find (pred==2));
wanted_points_cnts= data(wanted_points,1);
detected=table(wanted_points(:),wanted_points_cnts(:));
scatter(wanted_points,wanted_points_cnts)
drawnow