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double and float......

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Join Date: Sep 2007

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Reputation: vinaychalluru is an unknown quantity at this point

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vinaychalluru vinaychalluru is offline

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double and float......

Oct 25th, 2007

Hi,every one.I am new to C language and there I had tried a program as here and I got an output from what I had expected and hope you will help in this aspect and I have given the program as an attachment for better viewing of it.

thank you
vinaychalluru

Attached Files

my program.txt (517 Bytes, 2 views)

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Join Date: Oct 2007

Posts: 62

Reputation: Ptolemy is an unknown quantity at this point

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Ptolemy

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Junior Poster in Training

Re: double and float......

Oct 25th, 2007

It's better to put the code directly in your post if it's short. The problem is that floating-point values aren't always exact, so you can't reliably test for equality. The usual fix for your problem is to do a "close enough" test using the difference of the two values and a suitably small epsilon value:

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 c Syntax (Toggle Plain Text) 
#include <stdio.h>
#include <math.h>
 
static double floating_epsilon ( int precision )
{
  double result = 0.1;
 
  while ( --precision >= 0 )
    result /= 10;
 
  return result;
}
 
int main ( void )
{
  float a = 1.1;
  double b = 1.1;
 
  if ( fabs ( a - b ) <= floating_epsilon ( 1 ) )
    printf("Both are equal\n");
  else
    printf("Both of them are not equal\n");
 
  return 0;
}
#include <stdio.h>
#include <math.h>

static double floating_epsilon ( int precision )
{
  double result = 0.1;

  while ( --precision >= 0 )
    result /= 10;

  return result;
}

int main ( void )
{
  float a = 1.1;
  double b = 1.1;

  if ( fabs ( a - b ) <= floating_epsilon ( 1 ) )
    printf("Both are equal\n");
  else
    printf("Both of them are not equal\n");

  return 0;
}