This

Why can i compare 2 floats ?
if float a==float b print equal

re: This

Partender <savia755@latinmail.comwrote:Please see:
http://www.parashift.com/c++-faq-lit...html#faq-29.17

--
Marcus Kwok
Replace 'invalid' with 'net' to reply

re: This

Why can i compare 2 floats ?Typically this is due to the limits of numeric accuracy. For example,
in math class, 1.0 = .9999999(repeating), but in any finite
representation, these would be different. And since computers use
binary, even numbers like 1/5 have representations with repeating
decimals. So basically, a small round-off error or something like that
will get you.

The way you solve this is:
#include <math.h>
const double THRESHOLD = 1e-10; // or pick some other small value
if (fabs(a - b) < THRESHOLD) {
print equal;
}

re: This

Thanks Micheal and Marcus

I think I will try to again assemble my old hardware I used to lose and
throw away. No matter how old it is, it works good with my system. Very
nice I truly miss

re: This

Partender wrote:
Are you implying you will reassemble hardware where a program that compares
to floats for equality works correctly? Why not fix the floats?

--
Phlip
http://www.greencheese.us/ZeekLand <-- NOT a blog!!!

re: This

Phlip เขียน:Yes, I will but not now
Assembling a system has been my dream for years, old systems are easier
to work with than the modern ones.

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Partender wrote:Heh. If google groups is accurate, this is the same guy who calls
himself JJ in this thread:

http://groups.google.com/group/comp....0e4ba0637a7416

re: This

In article <1158686120.064738.6930@i42g2000cwa.googlegroups.c om>,
savia755@latinmail.com says...Unfortunately, most of the information in the FAQ on the sibject is
somewhere between misleading and downright wrong.

http://tinyurl.com/qcmyd

Shows one way to do floating point comparisons reasonably well, with the
proviso that it should really be renamed to reflect the fact that it
measures approximate equality.

--
Later,
Jerry.

The universe is a figment of its own imagination.

re: This

Jerry Coffin <jcoffin@taeus.comwrote:I was able to dig up this other article that has a few different
methods:

http://www.adtmag.com/joop/carticle.aspx?id=396

Of course, there is also the classic paper "What Every Computer
Scientist Should Know About Floating-Point Arithmetic" by David
Goldberg:

http://docs.sun.com/source/806-3568/...dberg.html#674

--
Marcus Kwok
Replace 'invalid' with 'net' to reply

re: This

Please us a post subject that describes the topic of you post.

On 2006-09-19, Partender <savia755@latinmail.comwrote: