Hi talents,
I have noticed that atof() function approximates the string I pass to
it.
when I use atof() , as atof(" 184.64")
and it returns 184.63999999999
But I would like to have the exact value that is passed.
Could anyone help me?
Thanks
Suresh Ooty
Apr 12 '06
21  8368 
asterisc skrev:
[snip] Indeed, very improbable, but not impossible. Anyway, i just wanted to
express that if you need to check if two floating numbers are equal,
then don't rely on the '==';
On the contrary. "==" is the only way to compare equality. Use your
EPSILON stuff to test for proximity, not for anything else.
[snip]
/Peter
asterisc wrote: Actually, it's extremely improbable that two objects of exactly the
same basic type, initialized using exactly the same expression, within
the same region of program text (same declaration even, sharing the
same set of declaration specifiers), will compare unequal.
Indeed, very improbable, but not impossible.
Sure. Cosmic rays, random hardware failures, etc. But when you use the
same expression to initialize values of the same type you get the same
value.
Anyway, i just wanted to express that if you need to check if two floating numbers are equal,
then don't rely on the '==';
And that is simply wrong. == tells you whether two floating-point values
are equal. If what you really want to know is whether they're
approximately equal, that's up to you. But when you do that you bring in
a new set of complications that most people who recommend this approach
haven't taken the time to understand.
--
Pete Becker
Roundhouse Consulting, Ltd. This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics | |
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