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 <dr> <save file 1> [<save file 2> ...]\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,*total;
  32         int slots;
  33         int i,j;
  34         double dr;
  35         int fd;
  36         unsigned char first;
  37
  38         if(argc<3) {
  39                 usage(argv[0]);
  40                 return -1;
  41         }
  42
  43         dr=atof(argv[1]);
  44
  45         first=1;
  46
  47         for(j=2;j<argc;j++) {
  48
  49                 memset(&moldyn,0,sizeof(t_moldyn));
  50
  51                 printf("[pair corr calc] reading save file ...\n");
  52                 ret=moldyn_read_save_file(&moldyn,argv[j]);
  53                 if(ret) {
  54                         printf("[pair corr calc] exit!\n");
  55                         return ret;
  56                 }
  57
  58                 moldyn.cutoff*=2;
  59                 moldyn.cutoff_square*=4;
  60
  61                 slots=moldyn.cutoff/dr;
  62                 printf("[pair corr calc]\n");
  63                 printf("  slots: %d\n",slots);
  64                 printf("  cutoff: %f\n",moldyn.cutoff);
  65                 printf("  dr: %f\n",dr);
  66
  67                 if(first) {
  68                         stat=(double *)malloc(3*slots*sizeof(double));
  69                         total=(double *)malloc(3*slots*sizeof(double));
  70                         first=0;
  71                         if(stat==NULL) {
  72                                 perror("[pair corr calc] alloc mem (stat)");
  73                                 return -1;
  74                         }
  75                         if(total==NULL) {
  76                                 perror("[pair corr calc] alloc mem (toal)");
  77                                 return -1;
  78                         }
  79                         memset(total,0,3*slots*sizeof(double));
  80                 }
  81
  82                 /* link cell init */
  83                 link_cell_init(&moldyn,VERBOSE);
  84
  85                 calculate_pair_correlation(&moldyn,dr,stat);
  86
  87                 for(i=0;i<3*slots;i++)
  88                         total[i]+=stat[i];
  89
  90         }
  91
  92         fd=open("pair_corr_func.txt",
  93                 O_WRONLY|O_CREAT|O_TRUNC,S_IRUSR|S_IWUSR);
  94         dprintf(fd,"#r #ab #aa #bb\n");
  95         for(i=0;i<slots;i++)
  96                 dprintf(fd,"%f %f %f %f\n",
  97                         i*dr,total[i],total[slots+i],total[2*slots+i]);
  98         close(fd);
  99
 100         free(stat);
 101         free(total);
 102
 103         moldyn_free_save_file(&moldyn);
 104
 105         return 0;
 106 }