/* This is a working version of the stars program that is
in the book. It deals correctly with data input, and gets
things a little bit organized, but it doesn't do any useful
calculations. */


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

#define DATAFILE "/magellan/users1/math/wtaylor/stars.data"

/* Field widths in the database */
#define RA_WIDTH   6
#define DECL_WIDTH 5
#define MAG_WIDTH  3
#define TYPE_WIDTH 6
#define CONSTELLATION_WIDTH 3

/* Data that will be taken from the data base for each star in turn: */

double ra_rads, decl_rads, magnitude;
char name[55];
char type[TYPE_WIDTH+1], constellation[CONSTELLATION_WIDTH+1];

main()
{
FILE *fp_in;
					/* FILE *fopen(); */
char dataline[100];
int N, i, Q, load(), display();
void error_1(), error_2(), label_picture(), get_user_data();

get_user_data();
fp_in = fopen(DATAFILE, "r");

N=0;
while (1)
{
for (i=0; i<100; i++) dataline[i]=0;
 Q = fscanf(fp_in,"%[^\n]\n",dataline);
 if (Q <= 0) {error_1(); break;}
 Q = load(dataline); if (Q <= 0) {error_2(); break;}
 display();
 N++;
}
fclose(fp_in);
label_picture();
}   /* END of MAIN */

int load(dataline)
char dataline[100];
{
int i, N, Q;
double ra_hours, ra_minutes, ra_seconds;
double decl_degrees, decl_minutes, decl_sign;
double u;
char ra[RA_WIDTH], decl[DECL_WIDTH], mag[MAG_WIDTH];

if (strlen(dataline)<RA_WIDTH+DECL_WIDTH+MAG_WIDTH) return(-2);
for (i=0; i<=50; i++)          name[i]=0;
for (i=0; i<=RA_WIDTH; i++)      ra[i]=0;
for (i=0; i<=DECL_WIDTH; i++)  decl[i]=0;
for (i=0; i<=MAG_WIDTH; i++)    mag[i]=0;
for (i=0; i<=TYPE_WIDTH; i++)  type[i]=0;
for (i=0; i<=CONSTELLATION_WIDTH; i++) constellation[i] = 0;
for (i=0; i<RA_WIDTH; i++)  (ra[i]=dataline[i]);
for (i=0; i<DECL_WIDTH; i++)  (decl[i]=dataline[i+RA_WIDTH]);
for (i=0; i<MAG_WIDTH; i++)  (mag[i]=dataline[i+RA_WIDTH+DECL_WIDTH]);
for (i=0; i<TYPE_WIDTH; i++)  (type[i]=dataline[i+RA_WIDTH+DECL_WIDTH+MAG_WIDTH]);
for (i=0; i<CONSTELLATION_WIDTH; i++) (constellation[i]=dataline[i+RA_WIDTH+DECL_WIDTH+MAG_WIDTH+TYPE_WIDTH]);
N = RA_WIDTH+DECL_WIDTH+MAG_WIDTH+TYPE_WIDTH+CONSTELLATION_WIDTH;
for (i=0; i<55; i++)  name[i]=dataline[i+N];
Q = sscanf(ra+0,"%2lf",&ra_hours);   if (Q<=0) return (-2);
Q = sscanf(ra+2,"%2lf",&ra_minutes);   if (Q<=0) return (-2);
Q = sscanf(ra+4,"%2lf",&ra_seconds);   if (Q<=0) return (-2);
switch(decl[0])
{
 case '+': decl_sign = 1.0; break;
 case '-': decl_sign = -1.0; break;
 default : return(-3);
}
Q = sscanf(decl+1,"%2lf",&decl_degrees);  if (Q<=0) return (-2);
Q = sscanf(decl+3,"%2lf",&decl_minutes);  if (Q<=0) return (-2);
/* calculate ra in radians */
{
 u = ra_hours + (ra_minutes/60.0) + (ra_seconds/(60.0*60.0));
 ra_rads = (u/24.0)*6.28318530718;   /* 24 hours = 6.28... radians */
}
/* calculate decl in radians: */
{
 u = decl_degrees + (decl_minutes/60.0);
 decl_rads = decl_sign*(u/360.0)*6.28318530718;   /* 360 degrees = 6.28... radians */
}
/* calculate magnitued:  */
switch(mag[0])
{
 case '-' :
 {
 Q = sscanf(mag+1,"%2lf",&magnitude); if (Q<=0) return(-2);
 magnitude = - magnitude/10.0;
 break;
 }
 default :
 {
 Q = sscanf(mag,"%3lf",&magnitude); if (Q<=0) return(-2);
 magnitude = magnitude/100.0;
 }
}
return (1);
}   /* END of LOAD */

int display()
{
 printf("\nThe name of the star is %s,",name);
 printf("\n              in the constellation %s", constellation);
 printf("\n       Its ra in radians is %4.5f", ra_rads);
 printf("\n       Its decl in radians is %4.5f", decl_rads);
 printf("\n       Its magnitude is %4.5f", magnitude);
 printf("\n       Its type is %s", type);
}


void label_picture()
{
}

void get_user_data()
{
}

void error_1()
{
	printf("error in reading data file");
}

void error_2()
{
	printf("error in scanning data");
}