forked from lijiext/lammps
54 lines
1.8 KiB
Plaintext
54 lines
1.8 KiB
Plaintext
"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
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:link(lws,http://lammps.sandia.gov)
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:link(ld,Manual.html)
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:link(lc,Section_commands.html#comm)
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:line
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compute sum command :h3
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[Syntax:]
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compute ID group-ID sum compute-ID1 compute-ID2 ... :pre
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ID, group-ID are documented in "compute"_compute.html command
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sum/ = style name of this compute command
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compute-ID1, 2, ... = IDs of computes that calculate per-atom quantities :ul
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[Examples:]
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compute 1 all sum c_force
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compute 1 all sum atomKE atomEpair atomEbond :pre
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[Description:]
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Define a computation that sums the results of one or more per-atom
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computes across all atoms in the group to yield a global scalar or
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vector quantity. For example, the forces on a group of atoms could be
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summed to yield a net force on the group. The resulting value(s) can
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be accessed by any command that uses global computes, e.g. the "thermo
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custom"_therml_style.html command or "fix ave/time"_fix_ave_time.html
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command or by a "variable"_variable.html command.
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Unlike the "compute sum/atom"_compute_sum_atom.html command, the
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result of this is not a per-atom quantity, but a global scalar or
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vector. If the other computes each generate a scalar value per atom,
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this compute will generate a single scalar value. If the other
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computes each generate a vector of values per atom, this compute will
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generate a vector of values where each value is the sum across atoms
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of the corresponding value produced by the other computes. In the
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latter case, all the other computes must generate per-atom vectors of
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the same size.
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Note that all per-atom computes generate values of 0.0 for atoms that
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are not in the group specified for that compute.
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[Restrictions:] none
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[Related commands:]
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"compute sum/atom"_compute_sum_atom.html
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[Default:] none
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