forked from lijiext/lammps
77 lines
2.1 KiB
C++
77 lines
2.1 KiB
C++
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/* ----------------------------------------------------------------------
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LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
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www.cs.sandia.gov/~sjplimp/lammps.html
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Steve Plimpton, sjplimp@sandia.gov, Sandia National Laboratories
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Copyright (2003) Sandia Corporation. Under the terms of Contract
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DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
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certain rights in this software. This software is distributed under
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the GNU General Public License.
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See the README file in the top-level LAMMPS directory.
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------------------------------------------------------------------------- */
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#include "math.h"
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#include "mpi.h"
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#include "min_sd.h"
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#include "atom.h"
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#include "update.h"
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#include "output.h"
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#include "timer.h"
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#define EPS 1.0e-6
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/* ----------------------------------------------------------------------
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minimization via steepest descent
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------------------------------------------------------------------------- */
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void MinSD::iterate(int n)
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{
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int i,fail;
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double alpha,dot,dotall;
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double *f;
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f = atom->f[0];
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for (int i = 0; i < ndof; i++) h[i] = f[i];
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neval = 0;
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for (niter = 0; niter < n; niter++) {
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update->ntimestep++;
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// line minimization along direction h from current atom->x
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eprevious = ecurrent;
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fail = (this->*linemin)(ndof,atom->x[0],h,ecurrent,dmin,dmax,alpha,neval);
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// if max_eval exceeded, all done
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// if linemin failed or energy did not decrease sufficiently, all done
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if (neval >= update->max_eval) break;
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if (fail || fabs(ecurrent-eprevious) <=
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update->tolerance * 0.5*(fabs(ecurrent) + fabs(eprevious) + EPS))
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break;
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// set h to new f = -Grad(x)
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// done if size sq of grad vector < EPS
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f = atom->f[0];
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dot = 0.0;
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for (i = 0; i < ndof; i++) dot += f[i]*f[i];
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MPI_Allreduce(&dot,&dotall,1,MPI_DOUBLE,MPI_SUM,world);
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if (dotall < EPS) break;
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for (i = 0; i < ndof; i++) h[i] = f[i];
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// output for thermo, dump, restart files
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if (output->next == update->ntimestep) {
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timer->stamp();
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output->write(update->ntimestep);
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timer->stamp(TIME_OUTPUT);
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}
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}
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}
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