what kind of algoritmh Should I use?
I have a dataset in wich I would like to detect a cluster, like the red dots in the attached simplified picture. I tried cluster analysis, outliers analysis by using several operators (lof, k-means, x-means, decision tree etc.) and even the auto model, but It seem I am not able to understand if I am on the right path and above all I don't know if the operators I chose are the right one. Might anybody help?