.. index:: partition

partition command
=================

Syntax
""""""

.. code-block:: LAMMPS

   partition style N command ...

* style = *yes* or *no*
* N = partition number (see asterisk form below)
* command = any LAMMPS command

Examples
""""""""

.. code-block:: LAMMPS

   partition yes 1 processors 4 10 6
   partition no 5 print "Active partition"
   partition yes *5 fix all nve
   partition yes 6* fix all nvt temp 1.0 1.0 0.1

Description
"""""""""""

This command invokes the specified command on a subset of the
partitions of processors you have defined via the :doc:`-partition command-line switch <Run_options>`.

Normally, every input script command in your script is invoked by
every partition.  This behavior can be modified by defining world- or
universe-style :doc:`variables <variable>` that have different values
for each partition.  This mechanism can be used to cause your script
to jump to different input script files on different partitions, if
such a variable is used in a :doc:`jump <jump>` command.

The "partition" command is another mechanism for having as input
script operate differently on different partitions.  It is basically a
prefix on any LAMMPS command.  The command will only be invoked on
the partition(s) specified by the *style* and *N* arguments.

If the *style* is *yes*, the command will be invoked on any partition
which matches the *N* argument.  If the *style* is *no* the command
will be invoked on all the partitions which do not match the Np
argument.

Partitions are numbered from 1 to Np, where Np is the number of
partitions specified by the :doc:`-partition command-line switch <Run_options>`.

*N* can be specified in one of two ways.  An explicit numeric value
can be used, as in the first example above.  Or a wild-card asterisk can
be used to span a range of partition numbers.  This takes the form "\*"
or "\*n" or "n\*" or "m\*n".  An asterisk with no numeric values means
all partitions from 1 to Np.  A leading asterisk means all partitions
from 1 to n (inclusive).  A trailing asterisk means all partitions
from n to Np (inclusive).  A middle asterisk means all partitions from
m to n (inclusive).

This command can be useful for the "run_style verlet/split" command
which imposed requirements on how the :doc:`processors <processors>`
command lays out a 3d grid of processors in each of 2 partitions.

Restrictions
""""""""""""
 none

Related commands
""""""""""""""""

:doc:`run_style verlet/split <run_style>`

Default
"""""""

none
