Recently I have started reading about principal component analysis. I have a big dataset (millions) which I will try to explain with 73 different variables. So I would like to reduce the number of variables so I will use this method.
I did the analysis and checked the scree plot. So I understood that I can use 8 components, I used "save principal components" by using red triangle and add this value. Now I have these results in my dataset.
What I could not understand (because of the various information in different sources) where I can see the components of each group. In principal components page I could view "formatted loading matrix". Is this the data I should see?(This is the one suggested in SAS report I believe).
On the other hand, a colleague advised me to do factor analysis after that and choose principal components again there. But then I should decide the number of components again. So if this is the case, how I can view these results and adapt it to my study? And some of my variables are correlated with each other. So, which oblique rotation I can go with? How can I decide that?