I want to use PCA in this kind of situation. I have three variables:
- how many times something happened for user - positive integer;
- total "power" of all happened events for user - real number, can be negative
- percent of "successful hits" - real positive number 0 < x < 1
Wikipedia states that "PCA is sensitive to the scaling of the variables."
A problem is that "power" can be measured using various units. And choice of units will affect the results. I do not see a natural choice of units for the moment.
Are there any suggestions on how to scale observations for PCA?