Liren Large Software Subsidy 7/07.iso/c/c021/7.img/EXAMPLES.ZIP/PLOTEMP.C

C/C++ Source or Header | 1990-05-04 | 5.4 KB | 204 lines

/* PLOTEMP.C--Example from Chapter 7 of Getting Started */

/* This program creates a table and a bar chart plot from a
   set of temperature readings */

#include <conio.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <graphics.h>

/* Prototypes */

void  get_temps(void);
void  table_view(void);
void  min_max(int num_vals, int vals[], int *min_val, int *max_val);
float avg_temp(int num_vals, int vals[]);
void  graph_view(void);
void  save_temps(void);
void  read_temps(void);

/* Global defines */

#define TRUE      1
#define READINGS  8

/* Global data structures */

int  temps[READINGS];

int  main(void)
{
   while (TRUE)
   {
      printf("\nTemperature Plotting Program Menu\n");
      printf("\tE - Enter temperatures for scratchpad\n");
      printf("\tS - Store scratchpad to disk\n");
      printf("\tR - Read disk file to scratchpad\n");
      printf("\tT - Table view of current data\n");
      printf("\tG - Graph view of current data\n");
      printf("\tX - Exit the program\n");
      printf("\nPress one of the above keys: ");

      switch (toupper(getche()))
      {
     case 'E': get_temps();  break;
     case 'S': save_temps(); break;
     case 'R': read_temps(); break;
     case 'T': table_view(); break;
     case 'G': graph_view(); break;
     case 'X': exit(0);
      }
   }
}

/* Function definitions */
void  get_temps(void)
{
   char inbuf[130];
   int  reading;

   printf("\nEnter temperatures, one at a time.\n");
   for (reading = 0; reading < READINGS; reading++)
   {
      printf("\nEnter reading # %d: ", reading + 1);
      gets(inbuf);
      sscanf(inbuf, "%d", &temps[reading]);
   }
}

void  table_view(void)
{
   int  reading, min, max;

   clrscr();                                /* clear the screen */
   printf("Reading\t\tTemperature(F)\n");

   for (reading = 0; reading < READINGS; reading++)
      printf("%d\t\t\t%d\n", reading + 1, temps[reading]);

   min_max(READINGS, temps, &min, &max);
   printf("Minimum temperature: %d\n", min);
   printf("Maximum temperature: %d\n", max);
   printf("Average temperature: %f\n", avg_temp(READINGS, temps));
}

void  min_max(int num_vals, int vals[], int *min_val, int *max_val)
{
   int  reading;

   *min_val = *max_val = vals[0];

   for (reading = 1; reading < num_vals; reading++)
   {
      if (vals[reading] < *min_val)
         *min_val = vals[reading];
      else if (vals[reading] > *max_val)
         *max_val = vals[reading];
   }
}

float avg_temp(int num_vals, int vals[])
{
   int  reading, total = 0;

   for (reading = 0; reading < num_vals; reading++)
      total += vals[reading];

   return   (float) total/reading;  /* reading equals total vals */
}

void  graph_view(void)
{
   int  graphdriver = DETECT, graphmode;
   int  reading, value;
   int  maxx, maxy, left, top, right, bottom, width;
   int  base;                          /* zero x-axis for graph */
   int  vscale = 1.5;       /* value to scale vertical bar size */
   int  space = 10;                     /* spacing between bars */

   char fprint[20];               /* formatted text for sprintf */

   initgraph(&graphdriver, &graphmode, "..\\bgi");
   if (graphresult() < 0)           /* make sure initialized OK */
      return;

   maxx  = getmaxx();              /* farthest right you can go */
   width = maxx /(READINGS + 1); /* scale and allow for spacing */
   maxy  = getmaxy() - 100;              /* leave room for text */
   left  = 25;
   right = width;
   base  = maxy / 2;              /* allow for neg values below */

   for (reading = 0; reading <  READINGS; reading++)
   {
      value = temps[reading] * vscale;
      if (value > 0)
      {
         top = base - value;            /* toward top of screen */
         bottom = base;
         setfillstyle(HATCH_FILL, 1);
      }
      else
      {
         top = base;
         bottom = base - value;      /* toward bottom of screen */
         setfillstyle(WIDE_DOT_FILL, 2);
      }
      bar(left, top, right, bottom);
      left  +=(width + space);       /* space over for next bar */
      right +=(width + space);        /* right edge of next bar */
   }

   outtextxy(0, base, "0 -");
   outtextxy(10, maxy + 20, "Plot of Temperature Readings");
   for (reading = 0; reading < READINGS; reading++)
   {
      sprintf(fprint, "%d", temps[reading]);
      outtextxy((reading *(width + space)) + 25, maxy + 40, fprint);
   }

   outtextxy(50, maxy+80, "Press any key to continue");

   getch();                               /* Wait for a key press */

   closegraph();
}

void  save_temps(void)
{
   FILE * outfile;
   char file_name[40];

   printf("\nSave to what filename? ");
   while (kbhit());  /* "eat" any char already in keyboard buffer */
   gets(file_name);

   if ((outfile = fopen(file_name,"wb")) == NULL)
   {
      perror("\nOpen failed! ");
      return;
   }
   fwrite(temps, sizeof(int), READINGS, outfile);
   fclose(outfile);
}

void  read_temps(void)
{
   FILE * infile;
   char file_name[40] = "test";

   printf("\nRead from which file? ");
   while (kbhit());  /* "eat" any char already in keyboard buffer */
   gets(file_name);

   if ((infile = fopen(file_name,"rb")) == NULL)
   {
      perror("\nOpen failed! ");
      return;
   }
   fread(temps, sizeof(int), READINGS, infile);
   fclose(infile);
}