[lammps-users] python tool

i am currently using the python tool of LAMMPS package. as a starting i used the crack example in LAMMPS to create the dump file.
i am getting an error like this when using the dumpsort.py program
[email protected]…1625…44…:~/scripting/python$ python dumpsort.py dump.crack 1 dump.new

read 0 snapshots
0 snapshots selected out of 0
no column assignments made
no unscaling could be performed
Sorting selected snapshots …

0 snapshots
i checked with some of the dumpfiles from my code also but got the same results. can anyone tell me what i am doing wrong?
i have done the steps as given in the README.txt of the python tool…
looking forward for your valuable suggestions…

This works fine for me:
% python dumpsort.py dump.crack 1 tmp.dump
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000
read 11 snapshots
11 snapshots selected out of 11
assigned columns: id type x y z
Unscaling dump ...
Sorting selected snapshots ...
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000
11 snapshots

Apparently, you are not reading the dump.crack file. Are
you in the right directory? Do you have the LAMMPS_TOOLS_PYTHON
env variable set, as the tools/python/README describes?

Note that there is a dump_modify sort option now which can
probably do what you want, internal to LAMMPS.