Syntax: +
+compute ID group-ID property/local input1 input2 ... ++
possible attributes = batom1 batom2 btype + aatom1 aatom2 aatom3 atype + datom1 datom2 datom3 dtype + iatom1 iatom2 iatom3 itype ++
batom1, batom2 = IDs of 2 atoms in each bond + btype = bond type of each bond + aatom1, aatom2, aatom3 = IDs of 3 atoms in each angle + atype = angle type of each angle + datom1, datom2, datom3, datom4 = IDs of 4 atoms in each dihedral + dtype = dihedral type of each dihedral + iatom1, iatom2, iatom3, iatom4 = IDs of 4 atoms in each improper + itype = improper type of each improper ++ +
Examples: +
+compute 1 all property/local btype batom1 batom2 +compute 1 all property/local atype aatom2 ++
Description: +
+Define a computation that simply stores the specified attributes as +local vectors or as columns of a local array. See the +compute command for a discussion of what local +quantities mean, and how they differ from per-atom quantities. Thus +if the input attributes are for bond information, the local vector or +array that is generated, when aggregated across all processors, will +contain information about all bonds in the system. +
+If multiple input attributes are specified then they must all generate +the same amount of information, so that the resulting local array has +the same number of rows for each column. This means that only bond +attributes can be specified together, or angle attributes, etc. Bond +and angle attributes can not be mixed in the same compute +property/local command. +
+The local data is generated by looping over all the atoms owned on a +processor and extracting bond, angle, etc info. For bonds, info about +an individual bond will only be included if both atoms in the bond are +in the specified compute group. Likewise for angles, dihedrals, etc. +
+Note that as atoms migrate from processor to processor, there will be +no consistent ordering of the entries within the local vector or array +from one timestep to the next. The only consistency that is +guaranteed is that the ordering on a particular timestep will be the +same for local info generated by other compute commands. For example, +output from the compute bond/local command +can be combined with bond atom indices from this command and output by +the dump local command in a consistent way. +
+The batom1 and batom2 attributes refer the atom IDs of the 2 atoms +in each bond. The btype attribute refers to the +type of the bond, from 1 to Nbtypes = # of bond types. The number of +bond types is defined in the data file read by the +read_data command. The attributes that start with +"a", "d", "i", refer to similar values for angles, +dihedrals, and impropers. +
+Output info: +
+This compute calculates a local vector or local array depending on the +number of input values. If a single input is specified, a local +vector is produced. If two or more inputs are specified, a local +array is produced where the number of columns = the number of inputs. +The vector or array can be accessed by any command that uses local +values from a compute as input. See this +section for an overview of LAMMPS output +options. +
+Restrictions: none +
+Related commands: +
+ +Default: none +
+ diff --git a/doc/compute_property_local.txt b/doc/compute_property_local.txt new file mode 100644 index 0000000000..430c1518c5 --- /dev/null +++ b/doc/compute_property_local.txt @@ -0,0 +1,94 @@ +"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c + +:link(lws,http://lammps.sandia.gov) +:link(ld,Manual.html) +:link(lc,Section_commands.html#comm) + +:line + +compute property/local command :h3 + +[Syntax:] + +compute ID group-ID property/local input1 input2 ... :pre + +ID, group-ID are documented in "compute"_compute.html command :ulb,l +property/local = style name of this compute command :l +input = one or more attributes :l + possible attributes = batom1 batom2 btype + aatom1 aatom2 aatom3 atype + datom1 datom2 datom3 dtype + iatom1 iatom2 iatom3 itype :pre + + batom1, batom2 = IDs of 2 atoms in each bond + btype = bond type of each bond + aatom1, aatom2, aatom3 = IDs of 3 atoms in each angle + atype = angle type of each angle + datom1, datom2, datom3, datom4 = IDs of 4 atoms in each dihedral + dtype = dihedral type of each dihedral + iatom1, iatom2, iatom3, iatom4 = IDs of 4 atoms in each improper + itype = improper type of each improper :pre +:ule + +[Examples:] + +compute 1 all property/local btype batom1 batom2 +compute 1 all property/local atype aatom2 :pre + +[Description:] + +Define a computation that simply stores the specified attributes as +local vectors or as columns of a local array. See the +"compute"_compute.html command for a discussion of what local +quantities mean, and how they differ from per-atom quantities. Thus +if the input attributes are for bond information, the local vector or +array that is generated, when aggregated across all processors, will +contain information about all bonds in the system. + +If multiple input attributes are specified then they must all generate +the same amount of information, so that the resulting local array has +the same number of rows for each column. This means that only bond +attributes can be specified together, or angle attributes, etc. Bond +and angle attributes can not be mixed in the same compute +property/local command. + +The local data is generated by looping over all the atoms owned on a +processor and extracting bond, angle, etc info. For bonds, info about +an individual bond will only be included if both atoms in the bond are +in the specified compute group. Likewise for angles, dihedrals, etc. + +Note that as atoms migrate from processor to processor, there will be +no consistent ordering of the entries within the local vector or array +from one timestep to the next. The only consistency that is +guaranteed is that the ordering on a particular timestep will be the +same for local info generated by other compute commands. For example, +output from the "compute bond/local"_compute_bond_local.html command +can be combined with bond atom indices from this command and output by +the "dump local"_dump.html command in a consistent way. + +The {batom1} and {batom2} attributes refer the atom IDs of the 2 atoms +in each "bond"_bond_style.html. The {btype} attribute refers to the +type of the bond, from 1 to Nbtypes = # of bond types. The number of +bond types is defined in the data file read by the +"read_data"_read_data.html command. The attributes that start with +"a", "d", "i", refer to similar values for "angles"_angle_style.html, +"dihedrals"_dihedral_style.html, and "impropers"_improper_style.html. + +[Output info:] + +This compute calculates a local vector or local array depending on the +number of input values. If a single input is specified, a local +vector is produced. If two or more inputs are specified, a local +array is produced where the number of columns = the number of inputs. +The vector or array can be accessed by any command that uses local +values from a compute as input. See "this +section"_Section_howto.html#4_15 for an overview of LAMMPS output +options. + +[Restrictions:] none + +[Related commands:] + +"dump local"_dump.html, "compute reduce"_compute_reduce.html + +[Default:] none