[gmx-users] template.c

[Chih-Ying Lin]

Hi :
I have difficulties to understand the following three files, which are
in Gromacs Package.
1.  template.c
2.  README
3.  Makefile.x86_64-unknown-linux-gnu


Please tell me if I have to do part 3 to compile template.c.

Thank you
Lin


============= [ TEMPLATE.C ]
===================================================================
/*
 * $Id: template.c,v 1.5 2008/05/29 08:36:53 hess Exp $
 *
 *                This source code is part of
 *
 *                 G   R   O   M   A   C   S
 *
 *          GROningen MAchine for Chemical Simulations
 *
 *                        VERSION 3.0
 *
 * Copyright (c) 1991-2001
 * BIOSON Research Institute, Dept. of Biophysical Chemistry
 * University of Groningen, The Netherlands
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * If you want to redistribute modifications, please consider that
 * scientific software is very special. Version control is crucial -
 * bugs must be traceable. We will be happy to consider code for
 * inclusion in the official distribution, but derived work must not
 * be called official GROMACS. Details are found in the README & COPYING
 * files - if they are missing, get the official version at www.gromacs.org.
 *
 * To help us fund GROMACS development, we humbly ask that you cite
 * the papers on the package - you can find them in the top README file.
 *
 * Do check out http://www.gromacs.org , or mail us at gromacs at gromacs.org .
 *
 * And Hey:
 * Gyas ROwers Mature At Cryogenic Speed
 */

/* This line is only for CVS version info */
static char *SRCID_template_c = "$Id: template.c,v 1.5 2008/05/29 08:36:53 hess
Exp $";

#include "statutil.h"
#include "typedefs.h"
#include "smalloc.h"
#include "vec.h"
#include "copyrite.h"
#include "statutil.h"
#include "tpxio.h"


int main(int argc,char *argv[])
{
  static char *desc[] = {
    "this is a small test program meant to serve as a template ",
    "when writing your own analysis tools. The advantage of ",
    "using gromacs for this is that you have access to all ",
    "information in the topology, and your program will be ",
    "able to handle all types of coordinates and trajectory ",
    "files supported by gromacs. Go ahead and try it! ",
    "This test version just writes the coordinates of an ",
    "arbitrary atom to standard out for each frame. You can ",
    "select which atom you want to examine with the -n argument."
  };

  static int n=1;

  /* Extra arguments - but note how you always get the begin/end
   * options when running the program, without mentioning them here!
   */

  t_pargs pa[] = {
    { "-n", FALSE, etINT, {&n},
      "Plot data for atom number n (starting on 1)"
    }
  };

  t_topology top;
  int        ePBC;
  char       title[STRLEN];
  t_trxframe fr;
  rvec       *xtop;
  matrix     box;
  int        status;
  int        flags = TRX_READ_X;

  t_filenm fnm[] = {
    { efTPS,  NULL,  NULL, ffREAD },   /* this is for the topology */
    { efTRX, "-f", NULL, ffREAD }      /* and this for the trajectory */
  };

#define NFILE asize(fnm)

  CopyRight(stderr,argv[0]);

  /* This is the routine responsible for adding default options,
   * calling the X/motif interface, etc. */
  parse_common_args(&argc,argv,PCA_CAN_TIME | PCA_CAN_VIEW,
                    NFILE,fnm,asize(pa),pa,asize(desc),desc,0,NULL);

  /* We don't need any topology information to write the coordinates,
   * but to show how it works we start by writing the name and
   * charge of the selected atom. It returns a boolean telling us
   * whether the topology was found and could be read
   */

  read_tps_conf(ftp2fn(efTPS,NFILE,fnm),title,&top,&ePBC,&xtop,NULL,box,TRUE);
  sfree(xtop);

  n=n-1; /* Our enumeration started on 1, but C starts from 0 */
  /* check that this atom exists */
  if(n<0 || n>(top.atoms.nr))
  {
    printf("Error: Atom number %d is out of range.\n",n);
    exit(1);
  }

  printf("Atom name: %s\n",*(top.atoms.atomname[n]));
  printf("Atom charge: %f\n",top.atoms.atom[n].q);

  /* The first time we read data is a little special */
  read_first_frame(&status,ftp2fn(efTRX,NFILE,fnm),&fr,flags);

  /* This is the main loop over frames */
  do {
    /* coordinates are available in the vector fr.x
     * you can find this and all other structures in
     * the types directory under the gromacs include dir.
     * Note how flags determines wheter to read x/v/f!
     */
    printf("Coordinates at t=%8.3f : %8.5f %8.5f %8.5f\n",fr.time,fr.x[n][XX],fr
.x[n][YY],fr.x[n][ZZ]);
  } while(read_next_frame(status,&fr));

  thanx(stderr);

  return 0;
}







======================= [ README ]
=================================================================

[chihying at hpc-login2 template]$ more README
Once installed, this directory contains a Makefile and
a small program that you could use as a template when
writing your own analysis software.

A Makefile.arch is created for each architecture you install
with the correct paths and libraries. You will have to link
(or copy) the correct makefile to "Makefile" or use the -f
option to gmake in order to select a makefile.

----------------------------------------------------------

If you are reading this in the distribution directory,
there will be a Makefile.am which automake uses to
create a Makefile.in which in turn is converted to
a Makefile by the configure script. Note that this is
NOT the template makefile - it is called Template.mak,
and used to create Makefile.arch at build time.

You should NOT touch or copy Makefile.in unless you
really know what you are doing - it is a template file
used by the configure script to create the real Makefile.

If you want to use automake and autoconf yourself, look
in the contrib directory of the distribution.






=================== [ Makefile.x86_64-unknown-linux-gnu  ]
=======================================================

[chihying at hpc-login2 template]$ more Makefile.x86_64-unknown-linux-gnu
# Generated automatically from Makefile.in by configure.
#
# This is a Gromacs 3.0 template makefile for your own utility programs.
#
# Copy this file to whatever directory you are using for your own
# software and add more targets like the template one below.
#
# If you are using gmake it is relatively straightforward to add
# an include based on environment variables (like previous Gromacs versions)
# to select compiler flags and stuff automatically, but below it is static:
#

# Variables set by the configuration script:
LIBS         = -lmd_mpi -lgmx_mpi  -L/usr/lib64 -lnsl -lsrfftw -lsfftw
-lm   -lSM -lICE -
lX11
LDFLAGS      = -L/usr/usc/gromacs/4.0.5//lib
CFLAGS       = -O3 -fomit-frame-pointer -finline-functions -Wall
-Wno-unused -funroll-all
-loops -std=gnu99   -I/usr/usc/gromacs/4.0.5//include
-I/usr/usc/gromacs/4.0.5//include/g
romacs
CC           = mpicc
LD           = $(CC)

# The real make targets - note that most make programs support
# the shortcut $^ instead of listing all object files a second
# time, but we cannot count on it...

template:       template.o
                $(LD) $(LDFLAGS) -o $@ template.o $(LIBS)