Re: calculating MSD in tutorial LBM part3

[Jean-Noël Grad]

Dear Ahmad,

The MSD correlator has changed in 4.2. Calling method `.result()` now 
returns a N by 3 matrix, therefore the numpy sum applies to x,y,z 
triples and returns an array of length N.

Regarding .lag_times(), you probably made a typo (it takes an extra 
"s"). If not, could you please share with us the error message when 
calling that method, and the git commit you're currently using?

Best,
JN

On 11/17/20 5:18 PM, Ahmad Reza Motezakker wrote:
> Dear All,
>
>
> I was checking the third part of LBM tutorial 
> (http://espressomd.org/html/tutorials_html/04-lattice_boltzmann/04-lattice_boltzmann_part3.html)
>  and I noticed a point.
>
> As far as I know, The output of MSD correlator is in order of lag time, # of 
> points, MSD_x, MSD_y, and MSD_z (am I right?)
>
> In calculating the MSD, according to the code, it is going to sum all the five 
> columns (including lag time and the # o points) for each time step as follows:
>
> com_pos_msd_results.append(np.sum(com_pos_cor.result(), axis=1))
>
> That is how I understand, am I making a mistake?
>
> Moreover, the .lag_time() seems not working in the new versions.
>
> I really appreciate that if you let me know your opinion.
>
>
> Best Regards,
>
> Ahmad Reza