[gmx-users] g_energy=> Different Average values from the screen than calculation of .xvg?

[Chih-Ying Lin]

Hi
 After the command,
 g_energy  -f abc.edr -o abc.xvg

 the average values is printed out on the screen.
 Energy    Average         RMSD    Fluct.  Drift   Tot-Drift
 Potential   -267323         375.096         374.647         -0.12711
      -63.5543
 Kinetic       En.     51901.5         259.034         259.015
-0.02151        -10.7574
 Total         Energy  -215421         275.52  274.683
-0.14862        -74.3106
 Temperature   302.825         1.51136         1.51125
-0.00013        -0.06277
 Pressure      (bar)   0.963727        133.498         133.335
0.045602        22.8012
 Volume       221.643         0.362625        0.362424        8.36E-05
       0.041823
 Density       (SI)    990.272         1.62111         1.6202
-0.00038        -0.18852



 but the average values are different than calculation from the
 instantaneous data in the  abc.xvg

 I sum up all the instantaneous data in the abc.xvg and average them.
 I got different average data as those shown up on the screen after
 g_energy command.



How do the Gromacs get the average values, which shows up on the
screen directly after the command g_energy?

Thank you
Lin