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3.11. Dump styles

Classes that dump per-atom info to files are derived from the Dump class. To dump new quantities or in a new format, a new derived dump class can be added, but it is typically simpler to modify the DumpCustom class contained in the dump_custom.cpp file.

src/dump_atom.cpp is a simple example of a derived dump class.

Here is a brief description of methods you define in your new derived class. See src/dump.h for details.

Required	“pure” methods that must be overridden
init_style	initialize style-specific state before a run
write_header	write the header section of a snapshot of atoms
pack	pack a proc’s output data into a buffer
write_data	write a proc’s data to a file

Optional	methods that have a default or empty implementation
count	count the number of lines a processor will output
openfile	open the output file (override for custom I/O)
convert_string	convert atom data to a string buffer
write_footer	write a footer after each snapshot
pack_forward_comm	pack a buffer for forward ghost communication
unpack_forward_comm	unpack a forward communication buffer
pack_reverse_comm	pack a buffer for reverse ghost communication
unpack_reverse_comm	unpack a reverse communication buffer
modify_param	called when dump_modify is executed (optional)
extract	provide access to internal data (optional)

See the dump command and its custom style for a list of keywords for atom information that can already be dumped by DumpCustom. It includes options to dump per-atom info from Compute classes, so adding a new derived Compute class is one way to calculate new quantities to dump.

Note that new keywords for atom properties are not typically added to the dump custom command. Instead they are added to the compute property/atom command.