forked from lijiext/lammps
553 lines
35 KiB
HTML
553 lines
35 KiB
HTML
|
|
|
|
<!DOCTYPE html>
|
|
<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
|
|
<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
|
|
<head>
|
|
<meta charset="utf-8">
|
|
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
|
|
<title>compute reduce command — LAMMPS documentation</title>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<link rel="stylesheet" href="_static/css/theme.css" type="text/css" />
|
|
|
|
|
|
|
|
<link rel="stylesheet" href="_static/sphinxcontrib-images/LightBox2/lightbox2/css/lightbox.css" type="text/css" />
|
|
|
|
|
|
|
|
<link rel="top" title="LAMMPS documentation" href="index.html"/>
|
|
<link rel="up" title="Computes" href="computes.html"/>
|
|
<link rel="next" title="compute rigid/local command" href="compute_rigid_local.html"/>
|
|
<link rel="prev" title="compute rdf command" href="compute_rdf.html"/>
|
|
|
|
|
|
<script src="_static/js/modernizr.min.js"></script>
|
|
|
|
</head>
|
|
|
|
<body class="wy-body-for-nav" role="document">
|
|
|
|
<div class="wy-grid-for-nav">
|
|
|
|
|
|
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
|
|
<div class="wy-side-nav-search">
|
|
|
|
|
|
|
|
<a href="Manual.html" class="icon icon-home"> LAMMPS
|
|
|
|
|
|
|
|
</a>
|
|
|
|
|
|
<div role="search">
|
|
<form id="rtd-search-form" class="wy-form" action="search.html" method="get">
|
|
<input type="text" name="q" placeholder="Search docs" />
|
|
<input type="hidden" name="check_keywords" value="yes" />
|
|
<input type="hidden" name="area" value="default" />
|
|
</form>
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
<div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
|
|
|
|
|
|
|
|
<p class="caption"><span class="caption-text">User Documentation</span></p>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_intro.html">1. Introduction</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_start.html">2. Getting Started</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_commands.html">3. Commands</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_packages.html">4. Packages</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_accelerate.html">5. Accelerating LAMMPS performance</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_howto.html">6. How-to discussions</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_example.html">7. Example problems</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_perf.html">8. Performance & scalability</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_tools.html">9. Additional tools</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_modify.html">10. Modifying & extending LAMMPS</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_python.html">11. Python interface to LAMMPS</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_errors.html">12. Errors</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Section_history.html">13. Future and history</a></li>
|
|
</ul>
|
|
<p class="caption"><span class="caption-text">Index</span></p>
|
|
<ul class="current">
|
|
<li class="toctree-l1"><a class="reference internal" href="tutorials.html">Tutorials</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="commands.html">Commands</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="fixes.html">Fixes</a></li>
|
|
<li class="toctree-l1 current"><a class="reference internal" href="computes.html">Computes</a><ul class="current">
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_ackland_atom.html">compute ackland/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_angle.html">compute angle command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_angle_local.html">compute angle/local command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_angmom_chunk.html">compute angmom/chunk command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_basal_atom.html">compute basal/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_body_local.html">compute body/local command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_bond.html">compute bond command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_bond_local.html">compute bond/local command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_centro_atom.html">compute centro/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_chunk_atom.html">compute chunk/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_cluster_atom.html">compute cluster/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_cna_atom.html">compute cna/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_com.html">compute com command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_com_chunk.html">compute com/chunk command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_contact_atom.html">compute contact/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_coord_atom.html">compute coord/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_damage_atom.html">compute damage/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_dihedral.html">compute dihedral command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_dihedral_local.html">compute dihedral/local command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_dilatation_atom.html">compute dilatation/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_dipole_chunk.html">compute dipole/chunk command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_displace_atom.html">compute displace/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_dpd.html">compute dpd command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_dpd_atom.html">compute dpd/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_erotate_asphere.html">compute erotate/asphere command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_erotate_rigid.html">compute erotate/rigid command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_erotate_sphere.html">compute erotate/sphere command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_erotate_sphere_atom.html">compute erotate/sphere/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_event_displace.html">compute event/displace command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_fep.html">compute fep command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_group_group.html">compute group/group command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_gyration.html">compute gyration command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_gyration_chunk.html">compute gyration/chunk command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_heat_flux.html">compute heat/flux command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_hexorder_atom.html">compute hexorder/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_improper.html">compute improper command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_improper_local.html">compute improper/local command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_inertia_chunk.html">compute inertia/chunk command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_ke.html">compute ke command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_ke_atom.html">compute ke/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_ke_atom_eff.html">compute ke/atom/eff command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_ke_eff.html">compute ke/eff command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_ke_rigid.html">compute ke/rigid command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_meso_e_atom.html">compute meso/e/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_meso_rho_atom.html">compute meso/rho/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_meso_t_atom.html">compute meso/t/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_msd.html">compute msd command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_msd_chunk.html">compute msd/chunk command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_msd_nongauss.html">compute msd/nongauss command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_omega_chunk.html">compute omega/chunk command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_orientorder_atom.html">compute orientorder/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_pair.html">compute pair command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_pair_local.html">compute pair/local command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_pe.html">compute pe command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_pe_atom.html">compute pe/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_plasticity_atom.html">compute plasticity/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_pressure.html">compute pressure command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_property_atom.html">compute property/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_property_chunk.html">compute property/chunk command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_property_local.html">compute property/local command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_rdf.html">compute rdf command</a></li>
|
|
<li class="toctree-l2 current"><a class="current reference internal" href="#">compute reduce command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="#compute-reduce-region-command">compute reduce/region command</a><ul>
|
|
<li class="toctree-l3"><a class="reference internal" href="#syntax">Syntax</a></li>
|
|
<li class="toctree-l3"><a class="reference internal" href="#examples">Examples</a></li>
|
|
<li class="toctree-l3"><a class="reference internal" href="#description">Description</a></li>
|
|
<li class="toctree-l3"><a class="reference internal" href="#restrictions">Restrictions</a></li>
|
|
<li class="toctree-l3"><a class="reference internal" href="#related-commands">Related commands</a></li>
|
|
</ul>
|
|
</li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_rigid_local.html">compute rigid/local command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_saed.html">compute saed command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_slice.html">compute slice command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_contact_radius.html">compute smd/contact/radius command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_damage.html">compute smd/damage command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_hourglass_error.html">compute smd/hourglass/error command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_internal_energy.html">compute smd/internal/energy command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_plastic_strain.html">compute smd/plastic/strain command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_plastic_strain_rate.html">compute smd/plastic/strain/rate command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_rho.html">compute smd/rho command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_tlsph_defgrad.html">compute smd/tlsph/defgrad command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_tlsph_dt.html">compute smd/tlsph/dt command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_tlsph_num_neighs.html">compute smd/tlsph/num/neighs command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_tlsph_shape.html">compute smd/tlsph/shape command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_tlsph_strain.html">compute smd/tlsph/strain command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_tlsph_strain_rate.html">compute smd/tlsph/strain/rate command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_tlsph_stress.html">compute smd/tlsph/stress command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_triangle_mesh_vertices.html">compute smd/triangle/mesh/vertices</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_ulsph_num_neighs.html">compute smd/ulsph/num/neighs command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_ulsph_strain.html">compute smd/ulsph/strain command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_ulsph_strain_rate.html">compute smd/ulsph/strain/rate command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_ulsph_stress.html">compute smd/ulsph/stress command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_smd_vol.html">compute smd/vol command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_sna_atom.html">compute sna/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_sna_atom.html#compute-snad-atom-command">compute snad/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_sna_atom.html#compute-snav-atom-command">compute snav/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_stress_atom.html">compute stress/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_tally.html">compute force/tally command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_tally.html#compute-heat-flux-tally-command">compute heat/flux/tally command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_tally.html#compute-pe-tally-command">compute pe/tally command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_tally.html#compute-pe-mol-tally-command">compute pe/mol/tally command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_tally.html#compute-stress-tally-command">compute stress/tally command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp.html">compute temp command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp.html#compute-temp-kk-command">compute temp/kk command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_asphere.html">compute temp/asphere command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_body.html">compute temp/body command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_chunk.html">compute temp/chunk command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_com.html">compute temp/com command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_cs.html">compute temp/cs command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_deform.html">compute temp/deform command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_deform_eff.html">compute temp/deform/eff command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_drude.html">compute temp/drude command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_eff.html">compute temp/eff command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_partial.html">compute temp/partial command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_profile.html">compute temp/profile command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_ramp.html">compute temp/ramp command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_region.html">compute temp/region command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_region_eff.html">compute temp/region/eff command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_rotate.html">compute temp/rotate command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_temp_sphere.html">compute temp/sphere command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_ti.html">compute ti command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_torque_chunk.html">compute torque/chunk command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_vacf.html">compute vacf command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_vcm_chunk.html">compute vcm/chunk command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_voronoi_atom.html">compute voronoi/atom command</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="compute_xrd.html">compute xrd command</a></li>
|
|
</ul>
|
|
</li>
|
|
<li class="toctree-l1"><a class="reference internal" href="pairs.html">Pair Styles</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="bonds.html">Bonds</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="angles.html">Angle Styles</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="dihedrals.html">Dihedral Styles</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="impropers.html">Improper Styles</a></li>
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</nav>
|
|
|
|
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
|
|
|
|
|
|
<nav class="wy-nav-top" role="navigation" aria-label="top navigation">
|
|
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
|
|
<a href="Manual.html">LAMMPS</a>
|
|
</nav>
|
|
|
|
|
|
|
|
<div class="wy-nav-content">
|
|
<div class="rst-content">
|
|
<div role="navigation" aria-label="breadcrumbs navigation">
|
|
<ul class="wy-breadcrumbs">
|
|
<li><a href="Manual.html">Docs</a> »</li>
|
|
|
|
<li><a href="computes.html">Computes</a> »</li>
|
|
|
|
<li>compute reduce command</li>
|
|
<li class="wy-breadcrumbs-aside">
|
|
|
|
|
|
<a href="http://lammps.sandia.gov">Website</a>
|
|
<a href="Section_commands.html#comm">Commands</a>
|
|
|
|
</li>
|
|
</ul>
|
|
<hr/>
|
|
|
|
<div class="rst-footer-buttons" style="margin-bottom: 1em" role="navigation" aria-label="footer navigation">
|
|
|
|
<a href="compute_rigid_local.html" class="btn btn-neutral float-right" title="compute rigid/local command" accesskey="n">Next <span class="fa fa-arrow-circle-right"></span></a>
|
|
|
|
|
|
<a href="compute_rdf.html" class="btn btn-neutral" title="compute rdf command" accesskey="p"><span class="fa fa-arrow-circle-left"></span> Previous</a>
|
|
|
|
</div>
|
|
|
|
</div>
|
|
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
|
|
<div itemprop="articleBody">
|
|
|
|
<div class="section" id="compute-reduce-command">
|
|
<span id="index-0"></span><h1>compute reduce command</h1>
|
|
</div>
|
|
<div class="section" id="compute-reduce-region-command">
|
|
<h1>compute reduce/region command</h1>
|
|
<div class="section" id="syntax">
|
|
<h2>Syntax</h2>
|
|
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">compute</span> <span class="n">ID</span> <span class="n">group</span><span class="o">-</span><span class="n">ID</span> <span class="n">style</span> <span class="n">arg</span> <span class="n">mode</span> <span class="n">input1</span> <span class="n">input2</span> <span class="o">...</span> <span class="n">keyword</span> <span class="n">args</span> <span class="o">...</span>
|
|
</pre></div>
|
|
</div>
|
|
<ul>
|
|
<li><p class="first">ID, group-ID are documented in <a class="reference internal" href="compute.html"><span class="doc">compute</span></a> command</p>
|
|
</li>
|
|
<li><p class="first">style = <em>reduce</em> or <em>reduce/region</em></p>
|
|
<pre class="literal-block">
|
|
<em>reduce</em> arg = none
|
|
<em>reduce/region</em> arg = region-ID
|
|
region-ID = ID of region to use for choosing atoms
|
|
</pre>
|
|
</li>
|
|
<li><p class="first">mode = <em>sum</em> or <em>min</em> or <em>max</em> or <em>ave</em> or <em>sumsq</em> or <em>avesq</em></p>
|
|
</li>
|
|
<li><p class="first">one or more inputs can be listed</p>
|
|
</li>
|
|
<li><p class="first">input = x, y, z, vx, vy, vz, fx, fy, fz, c_ID, c_ID[N], f_ID, f_ID[N], v_name</p>
|
|
<pre class="literal-block">
|
|
x,y,z,vx,vy,vz,fx,fy,fz = atom attribute (position, velocity, force component)
|
|
c_ID = per-atom or local vector calculated by a compute with ID
|
|
c_ID[I] = Ith column of per-atom or local array calculated by a compute with ID, I can include wildcard (see below)
|
|
f_ID = per-atom or local vector calculated by a fix with ID
|
|
f_ID[I] = Ith column of per-atom or local array calculated by a fix with ID, I can include wildcard (see below)
|
|
v_name = per-atom vector calculated by an atom-style variable with name
|
|
</pre>
|
|
</li>
|
|
<li><p class="first">zero or more keyword/args pairs may be appended</p>
|
|
</li>
|
|
<li><p class="first">keyword = <em>replace</em></p>
|
|
<pre class="literal-block">
|
|
<em>replace</em> args = vec1 vec2
|
|
vec1 = reduced value from this input vector will be replaced
|
|
vec2 = replace it with vec1[N] where N is index of max/min value from vec2
|
|
</pre>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="section" id="examples">
|
|
<h2>Examples</h2>
|
|
<pre class="literal-block">
|
|
compute 1 all reduce sum c_force
|
|
compute 1 all reduce/region subbox sum c_force
|
|
compute 2 all reduce min c_press[2] f_ave v_myKE
|
|
compute 2 all reduce min c_press[*] f_ave v_myKE
|
|
compute 3 fluid reduce max c_index[1] c_index[2] c_dist replace 1 3 replace 2 3
|
|
</pre>
|
|
</div>
|
|
<div class="section" id="description">
|
|
<h2>Description</h2>
|
|
<p>Define a calculation that “reduces” one or more vector inputs into
|
|
scalar values, one per listed input. The inputs can be per-atom or
|
|
local quantities; they cannot be global quantities. Atom attributes
|
|
are per-atom quantities, <a class="reference internal" href="compute.html"><span class="doc">computes</span></a> and <a class="reference internal" href="fix.html"><span class="doc">fixes</span></a>
|
|
may generate any of the three kinds of quantities, and <a class="reference internal" href="variable.html"><span class="doc">atom-style variables</span></a> generate per-atom quantities. See the
|
|
<a class="reference internal" href="variable.html"><span class="doc">variable</span></a> command and its special functions which can
|
|
perform the same operations as the compute reduce command on global
|
|
vectors.</p>
|
|
<p>The reduction operation is specified by the <em>mode</em> setting. The <em>sum</em>
|
|
option adds the values in the vector into a global total. The <em>min</em>
|
|
or <em>max</em> options find the minimum or maximum value across all vector
|
|
values. The <em>ave</em> setting adds the vector values into a global total,
|
|
then divides by the number of values in the vector. The <em>sumsq</em>
|
|
option sums the square of the values in the vector into a global
|
|
total. The <em>avesq</em> setting does the same as <em>sumsq</em>, then divdes the
|
|
sum of squares by the number of values. The last two options can be
|
|
useful for calculating the variance of some quantity, e.g. variance =
|
|
sumsq - ave^2.</p>
|
|
<p>Each listed input is operated on independently. For per-atom inputs,
|
|
the group specified with this command means only atoms within the
|
|
group contribute to the result. For per-atom inputs, if the compute
|
|
reduce/region command is used, the atoms must also currently be within
|
|
the region. Note that an input that produces per-atom quantities may
|
|
define its own group which affects the quantities it returns. For
|
|
example, if a compute is used as an input which generates a per-atom
|
|
vector, it will generate values of 0.0 for atoms that are not in the
|
|
group specified for that compute.</p>
|
|
<p>Each listed input can be an atom attribute (position, velocity, force
|
|
component) or can be the result of a <a class="reference internal" href="compute.html"><span class="doc">compute</span></a> or
|
|
<a class="reference internal" href="fix.html"><span class="doc">fix</span></a> or the evaluation of an atom-style
|
|
<a class="reference internal" href="variable.html"><span class="doc">variable</span></a>.</p>
|
|
<p>Note that for values from a compute or fix, the bracketed index I can
|
|
be specified using a wildcard asterisk with the index to effectively
|
|
specify multiple values. This takes the form “*” or “*n” or “n*” or
|
|
“m*n”. If N = the size of the vector (for <em>mode</em> = scalar) or the
|
|
number of columns in the array (for <em>mode</em> = vector), then an asterisk
|
|
with no numeric values means all indices from 1 to N. A leading
|
|
asterisk means all indices from 1 to n (inclusive). A trailing
|
|
asterisk means all indices from n to N (inclusive). A middle asterisk
|
|
means all indices from m to n (inclusive).</p>
|
|
<p>Using a wildcard is the same as if the individual columns of the array
|
|
had been listed one by one. E.g. these 2 compute reduce commands are
|
|
equivalent, since the <a class="reference internal" href="compute_stress_atom.html"><span class="doc">compute stress/atom</span></a>
|
|
command creates a per-atom array with 6 columns:</p>
|
|
<pre class="literal-block">
|
|
compute myPress all stress/atom NULL
|
|
compute 2 all reduce min myPress[*]
|
|
compute 2 all reduce min myPress[1] myPress[2] myPress[3] &
|
|
myPress[4] myPress[5] myPress[6]
|
|
</pre>
|
|
<hr class="docutils" />
|
|
<p>The atom attribute values (x,y,z,vx,vy,vz,fx,fy,fz) are
|
|
self-explanatory. Note that other atom attributes can be used as
|
|
inputs to this fix by using the <a class="reference internal" href="compute_property_atom.html"><span class="doc">compute property/atom</span></a> command and then specifying
|
|
an input value from that compute.</p>
|
|
<p>If a value begins with “c_”, a compute ID must follow which has been
|
|
previously defined in the input script. Computes can generate
|
|
per-atom or local quantities. See the individual
|
|
<a class="reference internal" href="compute.html"><span class="doc">compute</span></a> doc page for details. If no bracketed integer
|
|
is appended, the vector calculated by the compute is used. If a
|
|
bracketed integer is appended, the Ith column of the array calculated
|
|
by the compute is used. Users can also write code for their own
|
|
compute styles and <a class="reference internal" href="Section_modify.html"><span class="doc">add them to LAMMPS</span></a>. See the
|
|
discussion above for how I can be specified with a wildcard asterisk
|
|
to effectively specify multiple values.</p>
|
|
<p>If a value begins with “f_”, a fix ID must follow which has been
|
|
previously defined in the input script. Fixes can generate per-atom
|
|
or local quantities. See the individual <a class="reference internal" href="fix.html"><span class="doc">fix</span></a> doc page for
|
|
details. Note that some fixes only produce their values on certain
|
|
timesteps, which must be compatible with when compute reduce
|
|
references the values, else an error results. If no bracketed integer
|
|
is appended, the vector calculated by the fix is used. If a bracketed
|
|
integer is appended, the Ith column of the array calculated by the fix
|
|
is used. Users can also write code for their own fix style and <a class="reference internal" href="Section_modify.html"><span class="doc">add them to LAMMPS</span></a>. See the discussion above for how
|
|
I can be specified with a wildcard asterisk to effectively specify
|
|
multiple values.</p>
|
|
<p>If a value begins with “v_”, a variable name must follow which has
|
|
been previously defined in the input script. It must be an
|
|
<a class="reference internal" href="variable.html"><span class="doc">atom-style variable</span></a>. Atom-style variables can
|
|
reference thermodynamic keywords and various per-atom attributes, or
|
|
invoke other computes, fixes, or variables when they are evaluated, so
|
|
this is a very general means of generating per-atom quantities to
|
|
reduce.</p>
|
|
<hr class="docutils" />
|
|
<p>If the <em>replace</em> keyword is used, two indices <em>vec1</em> and <em>vec2</em> are
|
|
specified, where each index ranges from 1 to the # of input values.
|
|
The replace keyword can only be used if the <em>mode</em> is <em>min</em> or <em>max</em>.
|
|
It works as follows. A min/max is computed as usual on the <em>vec2</em>
|
|
input vector. The index N of that value within <em>vec2</em> is also stored.
|
|
Then, instead of performing a min/max on the <em>vec1</em> input vector, the
|
|
stored index is used to select the Nth element of the <em>vec1</em> vector.</p>
|
|
<p>Thus, for example, if you wish to use this compute to find the bond
|
|
with maximum stretch, you can do it as follows:</p>
|
|
<pre class="literal-block">
|
|
compute 1 all property/local batom1 batom2
|
|
compute 2 all bond/local dist
|
|
compute 3 all reduce max c_1[1] c_1[2] c_2 replace 1 3 replace 2 3
|
|
thermo_style custom step temp c_3[1] c_3[2] c_3[3]
|
|
</pre>
|
|
<p>The first two input values in the compute reduce command are vectors
|
|
with the IDs of the 2 atoms in each bond, using the <a class="reference internal" href="compute_property_local.html"><span class="doc">compute property/local</span></a> command. The last input
|
|
value is bond distance, using the <a class="reference internal" href="compute_bond_local.html"><span class="doc">compute bond/local</span></a> command. Instead of taking the
|
|
max of the two atom ID vectors, which does not yield useful
|
|
information in this context, the <em>replace</em> keywords will extract the
|
|
atom IDs for the two atoms in the bond of maximum stretch. These atom
|
|
IDs and the bond stretch will be printed with thermodynamic output.</p>
|
|
<hr class="docutils" />
|
|
<p>If a single input is specified this compute produces a global scalar
|
|
value. If multiple inputs are specified, this compute produces a
|
|
global vector of values, the length of which is equal to the number of
|
|
inputs specified.</p>
|
|
<p>As discussed below, for the <em>sum</em> and <em>sumsq</em> modes, the value(s)
|
|
produced by this compute are all “extensive”, meaning their value
|
|
scales linearly with the number of atoms involved. If normalized
|
|
values are desired, this compute can be accessed by the <a class="reference internal" href="thermo_style.html"><span class="doc">thermo_style custom</span></a> command with <a class="reference internal" href="thermo_modify.html"><span class="doc">thermo_modify norm yes</span></a> set as an option. Or it can be accessed by a
|
|
<a class="reference internal" href="variable.html"><span class="doc">variable</span></a> that divides by the appropriate atom count.</p>
|
|
<hr class="docutils" />
|
|
<p><strong>Output info:</strong></p>
|
|
<p>This compute calculates a global scalar if a single input value is
|
|
specified or a global vector of length N where N is the number of
|
|
inputs, and which can be accessed by indices 1 to N. These values can
|
|
be used by any command that uses global scalar or vector values from a
|
|
compute as input. See <a class="reference internal" href="Section_howto.html#howto-15"><span class="std std-ref">Section 6.15</span></a>
|
|
for an overview of LAMMPS output options.</p>
|
|
<p>All the scalar or vector values calculated by this compute are
|
|
“intensive”, except when the <em>sum</em> or <em>sumsq</em> modes are used on
|
|
per-atom or local vectors, in which case the calculated values are
|
|
“extensive”.</p>
|
|
<p>The scalar or vector values will be in whatever <a class="reference internal" href="units.html"><span class="doc">units</span></a> the
|
|
quantities being reduced are in.</p>
|
|
</div>
|
|
<div class="section" id="restrictions">
|
|
<h2>Restrictions</h2>
|
|
<blockquote>
|
|
<div>none</div></blockquote>
|
|
</div>
|
|
<div class="section" id="related-commands">
|
|
<h2>Related commands</h2>
|
|
<p><a class="reference internal" href="compute.html"><span class="doc">compute</span></a>, <a class="reference internal" href="fix.html"><span class="doc">fix</span></a>, <a class="reference internal" href="variable.html"><span class="doc">variable</span></a></p>
|
|
<p><strong>Default:</strong> none</p>
|
|
</div>
|
|
</div>
|
|
|
|
|
|
</div>
|
|
</div>
|
|
<footer>
|
|
|
|
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
|
|
|
|
<a href="compute_rigid_local.html" class="btn btn-neutral float-right" title="compute rigid/local command" accesskey="n">Next <span class="fa fa-arrow-circle-right"></span></a>
|
|
|
|
|
|
<a href="compute_rdf.html" class="btn btn-neutral" title="compute rdf command" accesskey="p"><span class="fa fa-arrow-circle-left"></span> Previous</a>
|
|
|
|
</div>
|
|
|
|
|
|
<hr/>
|
|
|
|
<div role="contentinfo">
|
|
<p>
|
|
© Copyright 2013 Sandia Corporation.
|
|
</p>
|
|
</div>
|
|
Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/snide/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
|
|
|
|
</footer>
|
|
|
|
</div>
|
|
</div>
|
|
|
|
</section>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
<script type="text/javascript">
|
|
var DOCUMENTATION_OPTIONS = {
|
|
URL_ROOT:'./',
|
|
VERSION:'',
|
|
COLLAPSE_INDEX:false,
|
|
FILE_SUFFIX:'.html',
|
|
HAS_SOURCE: true
|
|
};
|
|
</script>
|
|
<script type="text/javascript" src="_static/jquery.js"></script>
|
|
<script type="text/javascript" src="_static/underscore.js"></script>
|
|
<script type="text/javascript" src="_static/doctools.js"></script>
|
|
<script type="text/javascript" src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
|
|
<script type="text/javascript" src="_static/sphinxcontrib-images/LightBox2/lightbox2/js/jquery-1.11.0.min.js"></script>
|
|
<script type="text/javascript" src="_static/sphinxcontrib-images/LightBox2/lightbox2/js/lightbox.min.js"></script>
|
|
<script type="text/javascript" src="_static/sphinxcontrib-images/LightBox2/lightbox2-customize/jquery-noconflict.js"></script>
|
|
|
|
|
|
|
|
|
|
|
|
<script type="text/javascript" src="_static/js/theme.js"></script>
|
|
|
|
|
|
|
|
|
|
<script type="text/javascript">
|
|
jQuery(function () {
|
|
SphinxRtdTheme.StickyNav.enable();
|
|
});
|
|
</script>
|
|
|
|
|
|
</body>
|
|
</html> |