/** read sekibunkyu CAL output data **/
/** calculate average & standard deviation **/
/** 2013.12/19 by Akira Kadokura **/

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <math.h>

static char in_dir[]  ="/home/aurora/syowa_SPM/CAL_data/IntegrationSphere_CAL";


main(argc,argv)
    int argc;
    char *argv[];
{
	FILE *fin,*fout,*fopen();
	char fin_name[100],fout_name[100];

	char chead[255],ctime[18],cdat[10];
	float dat[2000];
	int i,imax,n,ns,ne;
	double sum,ave,std;

  /******************/
	if(argc != 4){
		printf("Please key-in (e.g. rdsekibunkyuCAL (directory name & file name) (read start #) (read end #)\n");
		exit(0);
	};

	ns = atoi(argv[2]);
	ne = atoi(argv[3]);

	sprintf(fin_name,"%s/%s",in_dir,argv[1]);
    fin = fopen(fin_name,"r");
	if(fin==0){
		printf("%s does not exist !!\n",fin_name);
		exit(0);
	};
printf("Data:%s\n",argv[1]);

  /** dummy read **/
	while(1){
		fgets(chead,255,fin);
		if(chead[3]==':' && chead[6]==':') break;
	};

  /** read time & output (V) data **/
   /** calculate average **/
  	i=-1;
	n=1;
	sum=0.0;

  	while(fgets(chead,255,fin)!=NULL){
		++n;
		if(n<ns) continue;
		if(n>ne) break;
		sscanf(chead,"%17s,%s",ctime,cdat);
		++i;
		dat[i] = atof(cdat);
		sum += dat[i];
    };
	imax = i+1;
	ave = sum/(double)imax;
 printf("imax:%d sum:%f ave:%f\n",imax,sum,ave);

   /** calculate standard deviation **/
	sum = 0.0;
	for(i=0;i<imax;i++){
		sum += pow((dat[i] - ave),2.0);
	};
	std = sqrt(sum/(double)imax);

	printf("average(V) & standard deviation (V)\n");
	printf("%f  %f\n",ave,std);

	fclose(fin);
};