[bug #22409] Minimisation of R1rho model give random results -- July 30, 2014 - 23:21

URL:
  <http://gna.org/bugs/?22409>

                 Summary: Minimisation of R1rho model give random results
                 Project: relax
            Submitted by: tlinnet
            Submitted on: Wed 30 Jul 2014 09:21:29 PM UTC
                Category: relax's source code
Specific analysis category: Relaxation dispersion
                Priority: 5 - Normal
                Severity: 4 - Important
                  Status: None
             Assigned to: bugman
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
                 Release: Repository: trunk
         Discussion Lock: Any
        Operating System: All systems

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Details:

This was discussed in:
http://thread.gmane.org/gmane.science.nmr.relax.devel/6538


Systemtest Relax_disp.test_r1rho_kjaergaard_auto_check_graphs 
shows that the error value constantly are changing between each
run of analysis.

This is properly because the number of Monte-Carlo simulation is only set to
3.

This can sometimes happens if the base data are exponential curves, as then
the R2eff errors are determined by Monte Carlo simulations which are random. 


And because it is a test the number of simulations are low so the randomness
is quite large.  

This randomness will then be propagated into the higher models. 

Apart from the unique case of Monte Carlo simulations (or the unit tests for
a
few other functions which use the 'random' Python module), a test
should return the same result to machine precision every single time.
It must be identical.




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