[gmx-users] gmx energy block averaging

[Andreas Mecklenfeld]

Dear Gromacs-users,

I've a question regarding the gmx energy functionality. I want to 
perform a block averaging with a prescribed number of data points in 
each block.

The manual section of this command says

"Note that in most cases the energy files contains averages over all MD 
steps, or over many more points than the number of frames in energy file."

which is in accordance with the information given for the 
nstenergy-parameter

"Note that the exact sums and fluctuations over all MD steps modulo 
nstcalcenergy are stored in the energy file, so g_energy can report 
exact energy averages and fluctuations also when nstenergy>1"

I'm aware that I can give the number of blocks for the gmx energy 
evaluation with -nbmin respectively -nbmax, though I'm uncertain about 
the number of data points gmx energy actually uses for the block 
averaging. Say, I've performed  1e6 steps with nstenergy = 1000 and I 
want 5000 points per block - do I need 200 blocks in total?

Thanks,
Andreas


-- 
M. Sc. Andreas Mecklenfeld
Stipendiat

Technische Universität Braunschweig
Institut für Thermodynamik
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38106 Braunschweig
Deutschland / Germany

Tel: +49 (0)531 391-2634
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