[lammps-users] unwrap coord and wrap coord

Hi all,

I got a dump file with wrapped coordinate “ux,uy,uz”. And I am writing a python code to convert the dump to a dump with unwrapped coordinate “x, y, z”. And I use the method “fmod” in numpy package to get the reminder of (wrapped coordinate)/(box length). And the unwrap coordinate is computed by (the origin of box) + (reminder). But I found the results deviates from the lammps results. For example, the x unwrapped coordinate in my code is 1.922400000000000020e+01, while the lammps given as 19.1946. The y and z coordinates seems right and is coincide with lammps results. Why is this difference? Is my computation wrong? Thanks.

Best regards.

Dongbo Wang