Help on multi-start-simulated-annealing sigmaA-weighted 2fofc map
Hi everyone, I read on the paper that they use CNS (model_map.inp) to calculate the avarage sigmaA-weighted 2fofc map. Right now I have set up the simulated annealing with different random seeds. I wonder whether phenix could calculate the average map with the multiple coordinates from different starts? Thanks! Fengyun
Hi Fengyun, - to run many SA with different random seeds: for random_seed in random_seeds: phenix.refine model.pdb data.mtz simulated_annealing=true main.random_seed=random_seed output.prefix=random_seed To create even broader variety, I would slightly shake the starting model: for random_seed in random_seeds: phenix.refine model.pdb data.mtz simulated_annealing=true main.random_seed=random_seed output.prefix=random_seed modify_start_model.sites.shake=0.3 Note, you will need to filter the outliers - refined models that have significantly higher R-factors compared to the rest.
I read on the paper that they use CNS (model_map.inp) to calculate the avarage sigmaA-weighted 2fofc map. Right now I have set up the simulated annealing with different random seeds. I wonder whether phenix could calculate the average map with the multiple coordinates from different starts?
Thanks!
With the multi-refined models, how can I make an average map for all
the models?
Can I do this in phenix?
Fengyun
引用 Pavel Afonine
Hi Fengyun,
- to run many SA with different random seeds:
for random_seed in random_seeds: phenix.refine model.pdb data.mtz simulated_annealing=true main.random_seed=random_seed output.prefix=random_seed
To create even broader variety, I would slightly shake the starting model:
for random_seed in random_seeds: phenix.refine model.pdb data.mtz simulated_annealing=true main.random_seed=random_seed output.prefix=random_seed modify_start_model.sites.shake=0.3
Note, you will need to filter the outliers - refined models that have significantly higher R-factors compared to the rest.
I read on the paper that they use CNS (model_map.inp) to calculate the avarage sigmaA-weighted 2fofc map. Right now I have set up the simulated annealing with different random seeds. I wonder whether phenix could calculate the average map with the multiple coordinates from different starts?
Hi Fengyun, my previous email actually doens't answer your question - I realized this after I pushed Sent button -:) To really answer your question I just wrote a Python script that does the following: - run multi-start Simulated Annealing, - combine all refined models into one multi-model PDB file (models separated by MODEL-ENDMDL records), and - compute averaged 2mFo-DFc map. The complete working example is here: http://cci.lbl.gov/~afonine/mssa/ You have two options at this point: - take this example, slightly change inputs by editing the run.py file (change input data and model file names, number of SA runs, etc) and run it as following: phenix.python run.py (since I spent 15 minutes on writing this script it's obviously not thoroughly tested or parameter-optimized, although I believe it should do the job right) or - wait a few days for one of the next PHENIX nightly builds where the above script will be available as a user-friendly either phenix.multi_start_sa command or an option of phenix.maps (I haven't decided yet what is better). Let me know if you have any questions. Pavel.
I read on the paper that they use CNS (model_map.inp) to calculate the avarage sigmaA-weighted 2fofc map. Right now I have set up the simulated annealing with different random seeds. I wonder whether phenix could calculate the average map with the multiple coordinates from different starts?
Thanks Pavel!
I am now running your script.
引用 Pavel Afonine
Hi Fengyun,
my previous email actually doens't answer your question - I realized this after I pushed Sent button -:)
To really answer your question I just wrote a Python script that does the following: - run multi-start Simulated Annealing, - combine all refined models into one multi-model PDB file (models separated by MODEL-ENDMDL records), and - compute averaged 2mFo-DFc map.
The complete working example is here:
http://cci.lbl.gov/~afonine/mssa/
You have two options at this point:
- take this example, slightly change inputs by editing the run.py file (change input data and model file names, number of SA runs, etc) and run it as following:
phenix.python run.py
(since I spent 15 minutes on writing this script it's obviously not thoroughly tested or parameter-optimized, although I believe it should do the job right)
or
- wait a few days for one of the next PHENIX nightly builds where the above script will be available as a user-friendly either phenix.multi_start_sa command or an option of phenix.maps (I haven't decided yet what is better).
Let me know if you have any questions.
Pavel.
I read on the paper that they use CNS (model_map.inp) to calculate the avarage sigmaA-weighted 2fofc map. Right now I have set up the simulated annealing with different random seeds. I wonder whether phenix could calculate the average map with the multiple coordinates from different starts?
participants (2)
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fn1@rice.edu
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Pavel Afonine