/*---------------------------------------------------*/

/*  Program chapter3_6                               */

/*                                                   */

/*  This program generates a summary report from     */

/*  a data file that has a trailer record with       */

/*  negative values.                                 */



#include <stdio.h>

#define FILENAME "sensor2.dat"



int main(void)

{

   /*  Declare and initialize variables.  */

   int num_data_pts=0, k;

   double time, motion, sum=0, max, min;

   FILE *sensor2;



   /*  Open file and read the first data points.  */

   sensor2 = fopen(FILENAME,"r");

   fscanf(sensor2,"%lf %lf",&time,&motion);



   /*  Initialize variables using first data points.  */

   max = min = motion;



   /*  Update summary data until trailier record read.  */

   do

   {

      sum += motion;

      if (motion > max)

	 max = motion;

      if (motion < min)

	 min = motion;

      num_data_pts++;

      fscanf(sensor2,"%lf %lf",&time,&motion);

   }  while (time >= 0);



   /*  Print summary information.  */

   printf("Number of sensor readings: %i \n",

	  num_data_pts);

   printf("Average reading:           %.2f \n",

	  sum/num_data_pts);

   printf("Maximum reading:           %.2f \n",max);

   printf("Minimum reading:           %.2f \n",min);



   /*  Close file and exit program.  */

   fclose(sensor2);

   return 0;

}

/*---------------------------------------------------*/