Dumping data files without headers ( just data in binary form)

Hello Everyone

I am dumping files with three velocity components for each atom every time step, using the dump command specified below.

dump vel all custom 16 dump_1_1.bin vx vy vz

Certainly, these files are really big and I am really interested on dumping them directly from LAMMPS without any header at the beginning of the file and especially without the labels that appears at the beginning of any time step.

Right now, I am post-processing these files with a FORTRAN code. My problem is that I have to save them in text form to later clean them, in order to get rid of headers and labels. Thus, this is a very time-consuming process due to their size. It would extremely advantageous for me to save them in binary form without any header (just data) in order to have them ready to be read by FORTRAN.

Does anyone know how to disable the headers in those files? Do I need to modify LAMMPS source files to do this?

Thanks,

Carlos Da Silva

Hello Everyone

I am dumping files with three velocity components for each atom every
time step, using the dump command specified below.

dump vel all custom 16 dump_1_1.bin vx vy vz

Certainly, these files are really big and I am really interested on
dumping them directly from LAMMPS without any header at the beginning of
the file and especially without the labels that appears at the beginning of
any time step.

Right now, I am post-processing these files with a FORTRAN code. My
problem is that I have to save them in text form to later clean them, in
order to get rid of headers and labels. Thus, this is a very time-consuming
process due to their size. It would extremely advantageous for me to save
them in binary form without any header (just data) in order to have them
ready to be read by FORTRAN.

Does anyone know how to disable the headers in those files? Do I need to
modify LAMMPS source files to do this?

i don't think there are that much savings. ​have you tried using​ the
transparent gzip compression? those space savings are usually much more.

axel.

Hello Everyone

I am dumping files with three velocity components for each atom every
time step, using the dump command specified below.

dump vel all custom 16 dump_1_1.bin vx vy vz

Certainly, these files are really big and I am really interested on
dumping them directly from LAMMPS without any header at the beginning of
the file and especially without the labels that appears at the beginning of
any time step.

Right now, I am post-processing these files with a FORTRAN code. My
problem is that I have to save them in text form to later clean them, in
order to get rid of headers and labels. Thus, this is a very time-consuming
process due to their size. It would extremely advantageous for me to save
them in binary form without any header (just data) in order to have them
ready to be read by FORTRAN.

Does anyone know how to disable the headers in those files? Do I need to
modify LAMMPS source files to do this?

​oh, and if you get to the point of being willing to modify source code. it
might be simpler and more general, to simply write a new compute style and
integrate your post-processing algorithm into LAMMPS directly.

axel.​