.. index:: fix sph/density/corr fix sph/density/corr command ============================ Syntax """""" .. parsed-literal:: fix ID group-ID sph/density/corr style args * ID, group-ID are documented in :doc:`fix ` command * sph/density/corr = style name of this fix command * style = *shepard* * args = list of arguments for a particular style .. parsed-literal:: *shepard* args = every nSteps nSteps = determes number of timesteps Examples """""""" .. parsed-literal:: fix corr all sph/density/corr shepard every 30 Description """"""""""" In general the pressure field in SPH exhibits large oscillations. One approach to overcome this problem is to perform a filter over the density. The filterstyle *shepard* is one of the most simple and quick correction. Every *nSteps* timesteps the following rule is applied: .. image:: Eqs/fix_sph_density_corr_eq1.jpg :align: center ---------- Restart, fix_modify, output, run start/stop, minimize info """""""""""""""""""""""""""""""""""""""""""""""""""""""""" No information about this fix is written to :doc:`binary restart files `. None of the :doc:`fix_modify ` options are relevant to this fix. No global scalar or vector or per_atom quantities are stored by this fix for access by various :ref:`output commands <4_15>`. No parameter of this fix can be used with the *start/stop* keywords of the :doc:`run ` command. This fix is not invoked during :doc:`energy minimization `. ---------- Restrictions """""""""""" none Related commands """""""""""""""" :doc:`pair_style sph/artVisc/tensCorr `, :doc:`fix sph/pressure `, :doc:`fix sph/density/continuity ` **Default:** none ---------- .. _LiuLiu2003: **(Liu and Liu, 2003)** "Smoothed Particle Hydrodynamics: A Meshfree Particle Method", G. R. Liu and M. B. Liu, World Scientific, p. 449 (2003). .. _liws: http://www.cfdem.com .. _ld: Manual.html .. _lc: Section_commands.html#comm