/*
Sample program to read the J-format magnetic data file. 
This program reads J-format data files and displays the data in each 1 minutes.
This program is compiled by Microsoft Visual C ver.4.0.
Standard functions of C are used in the program.
Therefore another C compiler will be able to compile this program.
The "Large memory model" should be used to compile this program.

Information of J-format is also seen on the Web page

http://denji102.geo.kyushu-u.ac.jp/denji/obs/equator/system/jformat.html

*/

/*  sample program		 ver.1.0	 1991/ 6/25  M.Shinohara */
/*						 ver.2.0	 1999/ 4/15  M.Shinohara */


#include   <stdio.h>
#include   <process.h>


/* subroutines in this program */
short dspinformation(char *readfile);
void readinformation(char *readfile,char *station,
			short *year, short *month, short *day, short *lt, short *dt,
			double *sensitivity);
void openmagdata(FILE **fp, char *readfile, short *basevalue);
void closemagdata(FILE *fp);
void read_1hour(FILE *fp, short *h, short *d, short *z,
					short *basevalue, short sampl_t);
void findmagdataposition(FILE *fp);
void calcbasevalue(FILE *fp, short *basevalue);



/*									1991/ 6/25  M.Shinohara */
/*									1999/ 4/15  M.Shinohara */

void main ( short argc , char *argv[] )
	{
	FILE *fp;
	
	static short h[3600],d[3600],z[3600];	/* magnetic data */
	short basevalue[3];					/* base value	*/
	short i,j,k,hour,min,sec,sampl_t;
	
	basevalue[0]=0;		/* initialize of basevalue */
	basevalue[1]=0;
	basevalue[2]=0;
	
	if ( argc < 2 )
		{
		printf("\nusage   : sampl_j p1 p2 p3...\n");
		printf(  "        :  p1 p2 p3... =  J-format data file name\n");
		printf(  "              1999/ 4/15 M.Shinohara, Kyushu University\n\n");
		printf(  "example : sampl_j r970926.msr\n");
		printf(  "        : sampl_j r990223.kuj r990224.kuj\n\n");
		exit(0);
		}
	
	for ( i=0; i<argc-1; ++i )
		{
			/* display file information*/
		sampl_t=dspinformation(argv[i+1]);
		openmagdata(&fp,argv[i+1],basevalue);
		
		for(j=0;j<24;++j)
			{
				/* read 1 hour magnetic data */
			read_1hour(fp,h,d,z,basevalue,sampl_t);
			
				/* output example of magnetic data */
				/* this example displaies time and magnetic data 
												each 1 minutes */
			for ( k=0; k<3600; k=k+60 )
			   {
				hour=j;			/* hour   */
				min=k/60;		/* minute */
				sec=k%60;		/* second */
											/* display */
				printf("%2d:%2d:%2d -> H=%8d   D=%8d   Z=%8d \n",
						hour,min,sec,h[k],d[k],z[k]);
				}
			}
		
		closemagdata(fp);
		printf("\n");
		}
	
	}



/* display file information */
/* parameter : 
	char *readfile  --- data file name   */
/*									 1991/ 6/25  M.Shinohara */
/*									 1999/ 4/15  M.Shinohara */

short dspinformation(char *readfile)
	{
	double sensitivity[3];		 /* sensitivity */
	char station[8];
	short year,month,day;
	short ltime,dt;
	
		/* read information part */
	readinformation(readfile,station,&year,&month,&day,
						&ltime,&dt,sensitivity);
	
	printf(" station = %8s \n",station);
	printf(" date	= %4d / %2d / %2d \n",year,month,day);
	printf(" local time	 =  %4d hour\n",ltime);
	printf(" sampling rate  =  %4d sec \n",dt);
	printf("sensitivity  ");
	printf("   H=%8.4lf",sensitivity[0]);
	printf("   D=%8.4lf",(float)sensitivity[1]);
	printf("   Z=%8.4lf\n",sensitivity[2]);
	
	return(dt);
	}



/* Read file information */
/* parameter : 
	char *readfile		--- data file name
	char *station		--- station name
	short *year			--- year
	short *month		--- month
	short *day			--- day
	short *ltime		--- local time
	short *dt			--- sampling rate 
	double *sensitivity --- sensitivity */
/*									 1991/ 6/25  M.Shinohara */
/*									 1999/ 4/15  M.Shinohara */

void readinformation(char *readfile, char *station, short *year,
				short *month, short *day, short *ltime, short *dt,
				double *sensitivity)
	{
	FILE *fp;
	char c[20];
	
	fp=fopen(readfile,"rt");   /* open data file */
	
	if ( fp==NULL )			 /* when can't find data file */
		{
		printf("data file is not found '%s' !\n",readfile);
		exit(0);
		}
	
		/* read some information */
	fscanf(fp,"%s",station);
	fscanf(fp,"%d %d %d",year,month,day);
	fscanf(fp,"\r\n LT= %d  DT= %d  %s",ltime,dt,c);
	fscanf(fp,"\r\n H= %le D= %le Z= %le",
					  sensitivity,sensitivity+1,sensitivity+2);
	
	fclose(fp);		/*close data file */
	
	return;
	}



/* Open magnetic data file */
/* parameter : 
	FILE **fp       --- file pointer of data file
	char *readfile  --- data file name
	short  *basevalue --- basevalue */
/*									 1991/ 6/25  M.Shinohara */
/*									 1999/ 4/15  M.Shinohara */

void openmagdata(FILE **fp, char *readfile, short *basevalue)
	{
	
	*fp=fopen(readfile,"rb");   /* open data file */
	
	if ( *fp==NULL )			 /* when can't find data file */
		{
		printf("data file is not found '%s' !\n",readfile);
		exit(0);
		}
	
		/* find start position of magnetic data */
	findmagdataposition(*fp);
	
		/* calculate today's basevalue */
	calcbasevalue(*fp,basevalue);
	
	return;
	}



/*									 1999/ 4/15  M.Shinohara */

void closemagdata(FILE *fp)
	{
	
	fclose(fp);		/*close data file */
	
	return;
	}



/* Read 1 hour magnetic data */
/* parameter : 
	FILE *fp			--- file pointer of data file
	short  *h			--- H component data
	short  *d			--- D component data
	short  *z			--- data array of 
	short *basevalue	--- basevalue 
	short sampl_t		--- sampling time of magnetic data*/
/*									 1991/ 6/25  M.Shinohara */
/*									 1999/ 4/15  M.Shinohara */

void read_1hour(FILE *fp, short *h, short *d, short *z,
					short *basevalue, short sampl_t)
	{
	short dbuff[3];
	short i,j;
	
	/* read and calculate magnetic data of each component */
	for ( i=0; i<3600; i=i+sampl_t )
		{
			/* read 1 hour data */
		fread((char *)dbuff,2,3,fp);
		
			/* calculate each component */
		for (j=i;j<i+sampl_t;++j)
			{
			h[j]=dbuff[0]+basevalue[0];
			d[j]=dbuff[1]+basevalue[1];
			z[j]=dbuff[2]+basevalue[2];
			}
		}
	
	return;
	}



/* Find start position of magnetic data part */
/* parameter : 
	FILE *fp		--- file pointer of data file */
/*									 1991/ 6/25  M.Shinohara */
/*									 1999/ 4/15  M.Shinohara */

void findmagdataposition(FILE *fp)
	{
	unsigned short data;
	
	/*rewind(fp);*/
	fseek(fp,0,0);
	
		/* find end code of information part ( 001A hex ) */
	do
		{
		fread((char *)&data,2,1,fp);
		}
	while( data != (unsigned short)0x1a );
	
	return;
	}



/* Read linkdata and calculate today's basevalue */
/* parameter : 
	FILE *fp			--- file pointer of data file
	short  *basevalue	--- basevalue */
/*									 1991/ 6/25  M.Shinohara */
/*									 1999/ 4/15  M.Shinohara */

void calcbasevalue(FILE *fp, short *basevalue)
	{
	short linkdata[3];		/*link data  */

		/* read linkdata */
	fread((char*)linkdata,2,3,fp);
	
		/* display linkdata */
	printf("linkvalue   H=%8d   D=%8d   Z=%8d\n",
				linkdata[0],linkdata[1],linkdata[2]);
	
		/* calculate today's basevalue */
	basevalue[0]=basevalue[0]+linkdata[0];
	basevalue[1]=basevalue[1]+linkdata[1];
	basevalue[2]=basevalue[2]+linkdata[2];
	
		/* display basevalue */
	printf("basevalue   H=%8d   D=%8d   Z=%8d\n",
				basevalue[0],basevalue[1],basevalue[2]);
	
	return;
	}