Does knnsearch guarantee points in ascending distance order?
1 Ansicht (letzte 30 Tage)
Ältere Kommentare anzeigen
Hi, I need to find the k-nearest neihgbors of a test point, but I also need to be sure that they are sorted in ascending order too. I have read the doc here: https://www.mathworks.com/help/stats/knnsearch.html There is this part when you use 'K' for name-value pair arguments: " IDX and D are my-by-K matrices. D sorts the distances in each row in ascending order. Each row in IDX contains the indices of the K closest neighbors in X corresponding to the K smallest distances in D. " It says that "D sorts sorts the distances in each row in ascending order" so IDX must be in ascending order as well right? I tried a simple script:
>> clear
>> Y = [0 0];
X = [100 10; 1 2; 0 3; 7 4; 10 2020; 30 27];
>> [idx,dist]=knnsearch(X,Y,'K',4)
idx =
2 3 4 6
dist =
2.2361 3.0000 8.0623 40.3609
>>
It appears to be sorted. But can I be sure that X(idx(1),:) is the 1st-nearest neighbor, X(idx(2),:) is the 2nd-nearest neighbor, and so on? Please help me, thank you very much :)
0 Kommentare
Antworten (0)
Siehe auch
Kategorien
Mehr zu Statistics and Machine Learning Toolbox finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!