pair_correlation_calc.c

   1 /*
   2  * calcultae pair correlation function
   3  *
   4  * author: frank.zirkelbach@physik.uni-augsburg.de
   5  *
   6  */
   7
   8 #define _GNU_SOURCE
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <string.h>
  13 #include <sys/types.h>
  14 #include <sys/stat.h>
  15 #include <fcntl.h>
  16
  17 #include "moldyn.h"
  18
  19 int usage(char *prog) {
  20
  21         printf("\nusage:\n");
  22         printf("  %s <save file> <dr>\n\n",prog);
  23
  24         return -1;
  25 }
  26
  27 int main(int argc,char **argv) {
  28
  29         t_moldyn moldyn;
  30         int ret;
  31         double *stat;
  32         int slots;
  33         int i;
  34         double dr;
  35         int fd;
  36
  37         if(argc!=3) {
  38                 usage(argv[0]);
  39                 return -1;
  40         }
  41
  42         memset(&moldyn,0,sizeof(t_moldyn));
  43
  44         printf("[pair corr calc] reading save file ...\n");
  45         ret=moldyn_read_save_file(&moldyn,argv[1]);
  46         if(ret) {
  47                 printf("[pair corr calc] exit!\n");
  48                 return ret;
  49         }
  50
  51         //moldyn.cutoff*=2;
  52         //moldyn.cutoff_square*=4;
  53
  54         dr=atof(argv[2]);
  55         slots=2.0*moldyn.cutoff/dr;
  56         printf("[pair corr calc]\n");
  57         printf("  slots: %d\n",slots);
  58         printf("  cutoff: %f\n",moldyn.cutoff);
  59         printf("  dr: %f\n",dr);
  60
  61         stat=(double *)malloc(3*slots*sizeof(double));
  62         if(stat==NULL) {
  63                 perror("[pair corr calc] alloc mem");
  64                 return -1;
  65         }
  66
  67         calculate_pair_correlation(&moldyn,dr,stat);
  68
  69         fd=open("pair_corr_func.txt",
  70                 O_WRONLY|O_CREAT|O_TRUNC,S_IRUSR|S_IWUSR);
  71         dprintf(fd,"#r #ab #aa #bb\n");
  72         for(i=0;i<slots;i++)
  73                 dprintf(fd,"%f %f %f %f\n",
  74                         i*dr,stat[i],stat[slots+i],stat[2*slots+i]);
  75         close(fd);
  76
  77         free(stat);
  78
  79         moldyn_free_save_file(&moldyn);
  80
  81         return 0;
  82 }