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*** Note *** === Warning ===I must warn you about using single field strength data.
If you play with the optimisation settings you can even find identical results to within machine precision - relax can mimic these other softwares.
=== Protocol ===
The key is that the full analysis protocol is rather complicated -
many people don't understand this - and that these softwares do not
1990).
* c) Eliminate failed models (this is only available in relax, <br>see thed'Auvergne and Gooley, 2006 model elimination paper athttp://dx.doi.org/10.1007/s10858-006-9007-z).
* d) Select the best model-free model for each spin system. <br>This againrequires precision modern techniques, with the best being AIC model
select (see the d'Auvergne and Gooley, 2003 model-free model selection
paper at http://dx.doi.org/10.1023/A:1021902006114). If you are
very, very small), then you should really look at that paper.
* e) Optimise the global model. <br>This is the diffusion tensor plus themodel-free models for all spin systems.
* f) Check for convergence (identical chi-squared values to a previousiteration, and not necessarily the last one). <br>If no, then go back tob) and repeat. Note that the chi-squared value can go up
significantly between iterations, but this is because the model is
simplifying itself at a much faster rate by loosing parameters - it's
relaxation data and the 3D structure or the system in study.
* g) Once steps a-f have been completed for all global models(characterised by the spheroid, prolate spheroid, oblate spheroid, and
ellipsoid diffusion tensors), then model selection between the
different global models needs to be performed.
* h) Monte Carlo simulations for error analysis must be performed at the end.
* i) Elimination of failed Monte Carlo simulations is essential for
keeping the errors to reasonable values for certain spin systems.
This is also a relax-only feature (see the d'Auvergne and Gooley, 2007
2008b paper at http://dx.doi.org/10.1007/s10858-007-9213-3) is fully
implemented in relax, however this required multiple field strength
data. This is a rather large script located at'''auto_anlayses/dauvergne_protocol.py'''. This protocol is used by the
GUI. So one option would be to copy this
'''auto_anlayses/dauvergne_protocol.py ''' script and modify it for the
figure 7.2 protocol.
It is now quite difficult to publish a model-free analysis with only
single field strength data as most of the field know about the
catastrophic analysis failures resulting in large amounts of
artificial motion. These T hese failures can also be much more subtle. Many
reviewers will ask for such data to be collected as the results cannot
not be trusted otherwise. For a model-free analysis, it is almost
Tjandra 1995 paper.
=== Recommendation ===
Finally, you will probably find it much easier to spend the 7-8 days
collecting data at another field strength than to implement the
