[phenixbb] Where to find optimized wxc_scale/wxu_scale weighting factors after optimization

Engin Ozkan eozkan at stanford.edu
Thu Aug 12 12:27:47 PDT 2010

  On 8/12/10 10:43 AM, Pavel Afonine wrote:
>> 1.  I would like to find the optimized weighting factors in the log file
>> but cannot.  Instead I find the following (pasted below).
> I'm wondering why you are trying to find them? It is such a technical 
> thing that changes from macro-cycle to macro-cycle...

Having the optimized weight printed would be mildly handy. First, the 
weight is probably not changing wildly between cycle to cycle, so an 
approximately working wxc_scale can be gotten. Then, this number can be 
used for quicker test runs with optimize_wxc=false, and you would not 
worry that your weights are hugely non-optimal for your quick runs.

Second, I recently realized that in the auto mode for optimize_wxc, my 
first cycle was not optimizing wxc, and I was getting huge jumps in 
geometry and R factors in the first cycle. If there was an obvious table 
showing wxc/wxu per cycle, it would take me shorter to realize what was 
going on. This first-cycle problem was serious, since it was breaking up 
all the sensible geometry that I spent days building in a 
low-resolution, large structure, which wasn't getting fixed in 
subsequent cycles (Obviously, setting optimize_wxc to every_cycle mode 
would have prevented this problem, but I bet you that most users aren't 
aware of such an option. You can also get the optimized wxc_scale by a 
simple multiplication if you dig into the log file, but that should not 
be necessary).

My refinement work is not linear; I don't go from Refine_1 to _2 to _3. 
A lot of the time, I will have 3a, 3b, 3c, etc. quick test runs to see 
how I should proceed next. "Quick" is the operative word here, and a 
roundabout good wxc_scale value is valuable there.


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