forked from lijiext/lammps
58 lines
1.6 KiB
HTML
58 lines
1.6 KiB
HTML
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<HTML>
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<CENTER><A HREF = "http://lammps.sandia.gov">LAMMPS WWW Page</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Chapter_commands.html#comm">LAMMPS Commands</A>
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</CENTER>
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<HR>
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<H3>min_style command
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</H3>
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<P><B>Syntax:</B>
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</P>
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<PRE>min_style style
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</PRE>
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<UL><LI>style = <I>cg</I> or <I>cg/fr</I> or <I>sd</I>
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</UL>
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<P><B>Examples:</B>
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</P>
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<PRE>min_style cg
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min_style sd
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</PRE>
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<P><B>Description:</B>
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</P>
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<P>Choose a minimization algorithm to use when a <A HREF = "minimize.html">minimize</A>
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command is performed.
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</P>
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<P>Style <I>cg</I> is the Polak-Ribiere (PR) version of the conjugate gradient
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(CG) algorithm. At each iteration the force gradient is combined with
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the previous iteration information to compute a new search direction
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perpendicular (conjugate) to previous search directions. The PR
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variant affects how the direction is chosen and how the CG method is
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restarted when it ceases to make progress. The PR variant is thought
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to be the most effective CG choice.
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</P>
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<P>Style <I>cg/fr</I> is the Fletcher-Reeves version of the conjugate gradient
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algorithm.
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</P>
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<P>Style <I>sd</I> is a steepest descent algorithm. At each iteration, the
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downhill direction corresponding to the force vector (negative
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gradient of energy) is searched along by a 1d line search. Typically,
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steepest descent will not converge as quickly as CG, but may be more
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robust in some situations.
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</P>
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<P><B>Restrictions:</B> none
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</P>
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<P><B>Related commands:</B>
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</P>
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<P><A HREF = "min_modify.html">min_modify</A>, <A HREF = "minimize.html">minimize</A>
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</P>
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<P><B>Default:</B>
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</P>
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<PRE>min_style cg
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</PRE>
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</HTML>
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