The decround() function

The rounding factor is 5x10^-s-1. To round a value, the decround() function adds the rounding factor to a positive number or subtracts this factor from a negative number. It then truncates to s digits, as the following table shows.

Value before round	Value of s	Rounded value
1.4	0	1.0
1.5	0	2.0
1.684	2	1.68
1.685	2	1.69
1.685	1	1.7
1.685	0	2.0

The file decround.ec in the demo directory contains the following sample program.

/*
   * decround.ec *

   The following program rounds a DECIMAL type number six times and displays
   the result of each operation.
*/

#include <stdio.h>

EXEC SQL include decimal;

char string[] = "-12345.038572";
char result[41];

main()
{
    mint x;
    mint i = 6;          /* number of decimal places to start with */
    dec_t num1;

    printf("DECROUND Sample ESQL Program running.\n\n");

    printf("String = %s\n", string);
    while(i)
      {
      if (x = deccvasc(string, strlen(string), &num1))
         {
         printf("Error %d in converting string to DECIMAL\n", x);
         break;
         }
      decround(&num1, i);
      if (x = dectoasc(&num1, result, sizeof(result), -1))
         {
         printf("Error %d in converting result to string\n", x);
         break;
         }
      result[40] = '\0';
      printf("  Rounded to %d Fractional Digits: %s\n", i--, result);
      }
    printf("\nDECROUND Sample Program over.\n\n");
}