why floor gives the wrong value?

Asked Oct 05 '15 at 14:17

Active Oct 05 '15 at 14:17

Viewed 52 times

Upon dividing 2.4/0.8 we will get output as 3.00 Upon applying floor am getting the output as 2.00 But my expectation is floor(2.4/0.8) == floor(3.00). But the result of floor(2.4/0.8) gives 2 instead of 3.

I can't visualize what is going wrong here.

#include<iostream>
#include <cmath>


int main()
{
   double d=2.4/0.8;

   printf("\n  :: %lf ",d);
   printf("\n  :: %lf ",floor(d)  );

   return 0;
}

OUTPUT:

 :: 3.000000
 :: 2.000000

asked Oct 05 '15 at 14:17

VINOTH ENERGETIC

1,775
4
23
38

6

Your value may be something like 2.999, and at the precision you requested this is printed as "3.00". – Kerrek SB Oct 05 '15 at 14:19
1

Try looking at the value in a debugger or printing with more digits. – crashmstr Oct 05 '15 at 14:20
2

[Floating point is inexact](http://floating-point-gui.de/). See the [actual value](http://coliru.stacked-crooked.com/a/d2cb3037ca4ebb02). – Angew is no longer proud of SO Oct 05 '15 at 14:20
@crashmstr: I blame it on poor software systems education! – Lightness Races in Orbit Oct 05 '15 at 15:29

why floor gives the wrong value?

0 Answers0