What's meaning about (aX aY)

[sunjmmeishao]

aX = cov(x_,y_)
aY = 0.5/n * ( ∑(x_^2) + ∑(y_^2) + sqrt( (∑(x_^2) + ∑(y_^2))^2 + 4 * cov(x_,y_)^2 ) )

What's meaning about (aX aY)
Look like The PCA is not say the principal vector is (aX aY)

[sunjmmeishao]

@edouard Siegel

[Nooba]

Hello sunjmmeishao,

I'm sorry I don't quite catch your meaning. Could you try and reformulate your question ?
Also, I have to say that I'm not the one behind the math of the PCA applied in this project, @PatrickNLT is. So I might not be able to help anyway.

Regards

[sunjmmeishao]

Hello Nooba,
It is nothing.I am a beginner,so have many question.

I expect the split partition is a rectangle， but the principal vector is an oblique line.
thanks!

[PatrickNLT]

Hi @sunjmmeishao ,

Being able to split using an oblique line is an important feature of ADClusterMapView. It makes it a valuable alternative to traditional clustering libraries that often use a quad tree. If you want to learn more about the algorithm, you can have a look at the blog post describing the approach we used back then: https://applidium.com/en/news/too_many_pins_on_your_map/