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dump_dcd.cpp
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Tue, Jul 30, 00:33

dump_dcd.cpp

/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. This software is distributed under
the GNU General Public License.
See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */
/* ----------------------------------------------------------------------
Contributing author: Naveen Michaud-Agrawal (Johns Hopkins U)
Axel Kohlmeyer (Temple U), support for groups
------------------------------------------------------------------------- */
#include <math.h>
#include <inttypes.h>
#include <stdio.h>
#include <time.h>
#include <string.h>
#include "dump_dcd.h"
#include "domain.h"
#include "atom.h"
#include "update.h"
#include "output.h"
#include "group.h"
#include "memory.h"
#include "error.h"
using namespace LAMMPS_NS;
#define NFILE_POS 8L
#define NSTEP_POS 20L
// necessary to set SEEK params b/c MPI-2 messes with these settings
#ifndef SEEK_SET
#define SEEK_SET 0
#define SEEK_CUR 1
#define SEEK_END 2
#endif
/* ---------------------------------------------------------------------- */
static inline void fwrite_int32(FILE* fd, uint32_t i)
{
fwrite(&i,sizeof(uint32_t),1,fd);
}
/* ---------------------------------------------------------------------- */
DumpDCD::DumpDCD(LAMMPS *lmp, int narg, char **arg) : Dump(lmp, narg, arg)
{
if (narg != 5) error->all(FLERR,"Illegal dump dcd command");
if (binary || compressed || multifile || multiproc)
error->all(FLERR,"Invalid dump dcd filename");
size_one = 3;
sort_flag = 1;
sortcol = 0;
unwrap_flag = 0;
format_default = NULL;
// allocate global array for atom coords
bigint n = group->count(igroup);
if (n > static_cast<bigint>(MAXSMALLINT/3/sizeof(float)))
error->all(FLERR,"Too many atoms for dump dcd");
natoms = static_cast<int> (n);
memory->create(coords,3*natoms,"dump:coords");
xf = &coords[0*natoms];
yf = &coords[1*natoms];
zf = &coords[2*natoms];
openfile();
headerflag = 0;
nevery_save = 0;
ntotal = 0;
}
/* ---------------------------------------------------------------------- */
DumpDCD::~DumpDCD()
{
memory->destroy(coords);
}
/* ---------------------------------------------------------------------- */
void DumpDCD::init_style()
{
if (sort_flag == 0 || sortcol != 0)
error->all(FLERR,"Dump dcd requires sorting by atom ID");
// check that dump frequency has not changed and is not a variable
int idump;
for (idump = 0; idump < output->ndump; idump++)
if (strcmp(id,output->dump[idump]->id) == 0) break;
if (output->every_dump[idump] == 0)
error->all(FLERR,"Cannot use variable every setting for dump dcd");
if (nevery_save == 0) nevery_save = output->every_dump[idump];
else if (nevery_save != output->every_dump[idump])
error->all(FLERR,"Cannot change dump_modify every for dump dcd");
}
/* ---------------------------------------------------------------------- */
void DumpDCD::openfile()
{
if (me == 0) {
fp = fopen(filename,"wb");
if (fp == NULL) error->one(FLERR,"Cannot open dump file");
}
}
/* ---------------------------------------------------------------------- */
void DumpDCD::write_header(bigint n)
{
if (n != natoms) error->all(FLERR,"Dump dcd of non-matching # of atoms");
if (update->ntimestep > MAXSMALLINT)
error->one(FLERR,"Too big a timestep for dump dcd");
// first time, write header for entire file
if (headerflag == 0) {
if (me == 0) write_dcd_header("Written by LAMMPS");
headerflag = 1;
nframes = 0;
}
// dim[] = size and angle cosines of orthogonal or triclinic box
// dim[0] = a = length of unit cell vector along x-axis
// dim[1] = gamma = cosine of angle between a and b
// dim[2] = b = length of unit cell vector in xy-plane
// dim[3] = beta = cosine of angle between a and c
// dim[4] = alpha = cosine of angle between b and c
// dim[5] = c = length of final unit cell vector
// 48 = 6 doubles
double dim[6];
if (domain->triclinic) {
double *h = domain->h;
double alen = h[0];
double blen = sqrt(h[5]*h[5] + h[1]*h[1]);
double clen = sqrt(h[4]*h[4] + h[3]*h[3] + h[2]*h[2]);
dim[0] = alen;
dim[2] = blen;
dim[5] = clen;
dim[4] = (h[5]*h[4] + h[1]*h[3]) / blen/clen; // alpha
dim[3] = (h[0]*h[4]) / alen/clen; // beta
dim[1] = (h[0]*h[5]) / alen/blen; // gamma
} else {
dim[0] = domain->xprd;
dim[2] = domain->yprd;
dim[5] = domain->zprd;
dim[1] = dim[3] = dim[4] = 0.0;
}
if (me == 0) {
uint32_t out_integer = 48;
fwrite_int32(fp,out_integer);
fwrite(dim,out_integer,1,fp);
fwrite_int32(fp,out_integer);
if (flush_flag) fflush(fp);
}
}
/* ---------------------------------------------------------------------- */
void DumpDCD::pack(tagint *ids)
{
int m,n;
tagint *tag = atom->tag;
double **x = atom->x;
imageint *image = atom->image;
int *mask = atom->mask;
int nlocal = atom->nlocal;
m = n = 0;
if (unwrap_flag) {
double xprd = domain->xprd;
double yprd = domain->yprd;
double zprd = domain->zprd;
double xy = domain->xy;
double xz = domain->xz;
double yz = domain->yz;
for (int i = 0; i < nlocal; i++) {
if (mask[i] & groupbit) {
int ix = (image[i] & IMGMASK) - IMGMAX;
int iy = (image[i] >> IMGBITS & IMGMASK) - IMGMAX;
int iz = (image[i] >> IMG2BITS) - IMGMAX;
if (domain->triclinic) {
buf[m++] = x[i][0] + ix * xprd + iy * xy + iz * xz;
buf[m++] = x[i][1] + iy * yprd + iz * yz;
buf[m++] = x[i][2] + iz * zprd;
} else {
buf[m++] = x[i][0] + ix * xprd;
buf[m++] = x[i][1] + iy * yprd;
buf[m++] = x[i][2] + iz * zprd;
}
ids[n++] = tag[i];
}
}
} else {
for (int i = 0; i < nlocal; i++)
if (mask[i] & groupbit) {
buf[m++] = x[i][0];
buf[m++] = x[i][1];
buf[m++] = x[i][2];
ids[n++] = tag[i];
}
}
}
/* ---------------------------------------------------------------------- */
void DumpDCD::write_data(int n, double *mybuf)
{
// copy buf atom coords into 3 global arrays
int m = 0;
for (int i = 0; i < n; i++) {
xf[ntotal] = mybuf[m++];
yf[ntotal] = mybuf[m++];
zf[ntotal] = mybuf[m++];
ntotal++;
}
// if last chunk of atoms in this snapshot, write global arrays to file
if (ntotal == natoms) {
write_frame();
ntotal = 0;
}
}
/* ---------------------------------------------------------------------- */
int DumpDCD::modify_param(int narg, char **arg)
{
if (strcmp(arg[0],"unwrap") == 0) {
if (narg < 2) error->all(FLERR,"Illegal dump_modify command");
if (strcmp(arg[1],"yes") == 0) unwrap_flag = 1;
else if (strcmp(arg[1],"no") == 0) unwrap_flag = 0;
else error->all(FLERR,"Illegal dump_modify command");
return 2;
}
return 0;
}
/* ----------------------------------------------------------------------
return # of bytes of allocated memory in buf and global coords array
------------------------------------------------------------------------- */
bigint DumpDCD::memory_usage()
{
bigint bytes = Dump::memory_usage();
bytes += memory->usage(coords,natoms*3);
return bytes;
}
/* ---------------------------------------------------------------------- */
void DumpDCD::write_frame()
{
// write coords
uint32_t out_integer = natoms*sizeof(float);
fwrite_int32(fp,out_integer);
fwrite(xf,out_integer,1,fp);
fwrite_int32(fp,out_integer);
fwrite_int32(fp,out_integer);
fwrite(yf,out_integer,1,fp);
fwrite_int32(fp,out_integer);
fwrite_int32(fp,out_integer);
fwrite(zf,out_integer,1,fp);
fwrite_int32(fp,out_integer);
// update NFILE and NSTEP fields in DCD header
nframes++;
out_integer = nframes;
fseek(fp,NFILE_POS,SEEK_SET);
fwrite_int32(fp,out_integer);
out_integer = update->ntimestep;
fseek(fp,NSTEP_POS,SEEK_SET);
fwrite_int32(fp,out_integer);
fseek(fp,0,SEEK_END);
}
/* ---------------------------------------------------------------------- */
void DumpDCD::write_dcd_header(const char *remarks)
{
uint32_t out_integer;
float out_float;
char title_string[200];
time_t cur_time;
struct tm *tmbuf;
int ntimestep = update->ntimestep;
out_integer = 84;
fwrite_int32(fp,out_integer);
strcpy(title_string,"CORD");
fwrite(title_string,4,1,fp);
fwrite_int32(fp,0); // NFILE = # of snapshots in file
fwrite_int32(fp,ntimestep); // START = timestep of first snapshot
fwrite_int32(fp,nevery_save); // SKIP = interval between snapshots
fwrite_int32(fp,ntimestep); // NSTEP = timestep of last snapshot
fwrite_int32(fp,0); // NAMD writes NSTEP or ISTART
fwrite_int32(fp,0);
fwrite_int32(fp,0);
fwrite_int32(fp,0);
fwrite_int32(fp,0);
out_float = update->dt;
fwrite(&out_float,sizeof(float),1,fp);
fwrite_int32(fp,1);
fwrite_int32(fp,0);
fwrite_int32(fp,0);
fwrite_int32(fp,0);
fwrite_int32(fp,0);
fwrite_int32(fp,0);
fwrite_int32(fp,0);
fwrite_int32(fp,0);
fwrite_int32(fp,0);
fwrite_int32(fp,24); // pretend to be Charmm version 24
fwrite_int32(fp,84);
fwrite_int32(fp,164);
fwrite_int32(fp,2);
strncpy(title_string,remarks,80);
title_string[79] = '\0';
fwrite(title_string,80,1,fp);
cur_time=time(NULL);
tmbuf=localtime(&cur_time);
memset(title_string,' ',81);
strftime(title_string,80,"REMARKS Created %d %B,%Y at %H:%M",tmbuf);
fwrite(title_string,80,1,fp);
fwrite_int32(fp,164);
fwrite_int32(fp,4);
fwrite_int32(fp,natoms); // number of atoms in each snapshot
fwrite_int32(fp,4);
if (flush_flag) fflush(fp);
}

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