On Tue, Jun 25, 2013 at 12:44 AM, Michael Kazekin <kazm...@hotmail.com> wrote: > But doesn't alternation guarantee convexity?
No, the problem remains non-convex. At each step, where half the parameters are fixed, yes that constrained problem is convex. But each of these is not the same as the overall global problem being solved. > Yeah, but then you start dealing with another problem, how to blend all > results together and how doing this affects overall quality of results (in > our case recommendations), right? No you would usually just take the best solution and use it alone. Or at least, that's a fine thing to do.