.. index:: write_dump write_dump command ================== Syntax """""" .. parsed-literal:: write_dump group-ID style file dump-args modify dump_modify-args * group-ID = ID of the group of atoms to be dumped * style = any of the supported :doc:`dump styles ` * file = name of file to write dump info to * dump-args = any additional args needed for a particular :doc:`dump style ` * modify = all args after this keyword are passed to :doc:`dump_modify ` (optional) * dump-modify-args = args for :doc:`dump_modify ` (optional) Examples """""""" .. parsed-literal:: write_dump all atom dump.atom write_dump subgroup atom dump.run.bin write_dump all custom dump.myforce.* id type x y vx fx write_dump flow custom dump.%.myforce id type c_myF[3] v_ke modify sort id write_dump all xyz system.xyz modify sort id elements O H write_dump all image snap*.jpg type type size 960 960 modify backcolor white write_dump all image snap*.jpg element element & bond atom 0.3 shiny 0.1 ssao yes 6345 0.2 size 1600 1600 & modify backcolor white element C C O H N C C C O H H S O H Description """"""""""" Dump a single snapshot of atom quantities to one or more files for the current state of the system. This is a one-time immediate operation, in contrast to the :doc:`dump ` command which will will set up a dump style to write out snapshots periodically during a running simulation. The syntax for this command is mostly identical to that of the :doc:`dump ` and :doc:`dump_modify ` commands as if they were concatenated together, with the following exceptions: There is no need for a dump ID or dump frequency and the keyword *modify* is added. The latter is so that the full range of :doc:`dump_modify ` options can be specified for the single snapshot, just as they can be for multiple snapshots. The *modify* keyword separates the arguments that would normally be passed to the *dump* command from those that would be given the *dump_modify*. Both support optional arguments and thus LIGGGHTS(R)-PUBLIC needs to be able to cleanly separate the two sets of args. Note that if the specified filename uses wildcard characters "*" or "%", as supported by the :doc:`dump ` commmand, they will operate in the same fashion to create the new filename(s). Normally, :doc:`dump image ` files require a filename with a "*" character for the timestep. That is not the case for the write_dump command; no wildcard "*" character is necessary. ---------- Restrictions """""""""""" All restrictions for the :doc:`dump ` and :doc:`dump_modify ` commands apply to this command as well, with the exception of the :doc:`dump image ` filename not requiring a wildcard "*" character, as noted above. Since dumps are normally written during a :doc:`run ` or :doc:`energy minimization `, the simulation has to be ready to run before this command can be used. Similarly, if the dump requires information from a compute, fix, or variable, the information needs to have been calculated for the current timestep (e.g. by a prior run), else LIGGGHTS(R)-PUBLIC will generate an error message. For example, it is not possible to dump per-atom energy with this command before a run has been performed, since no energies and forces have yet been calculated. See the :doc:`variable ` doc page sectinn on Variable Accuracy for more information on this topic. Related commands """""""""""""""" :doc:`dump `, :doc:`dump image `, :doc:`dump_modify ` Default """"""" The defaults are listed on the doc pages for the :doc:`dump ` and :doc:`dump image ` and :doc:`dump_modify ` commands. .. _liws: http://www.cfdem.com .. _ld: Manual.html .. _lc: Section_commands.html#comm