I have a 2D pdf (variables X and Y) that I use to fit some data. I would like then to project the data and the corresponding pdf with respect a particular axis, which is rotated with respect to the original X and Y. The rotation angle (theta) is a result of the 2D fit. I would like then to project on the X-prime axis which is a linear combination of X and Y,
X-prime = cos(theta)*X + sin(theta)*Y
Does any one knows if this is possible with RooFit?