Wolfram Hinderer wrote:
On 7 Jul., 19:32, Ethan Furman <et...@stoneleaf.us> wrote:
Nobody wrote:
On Wed, 07 Jul 2010 15:08:07 +0200, Thomas Jollans wrote:
you should never rely on a floating-point number to have exactly a
certain value.
"Never" is an overstatement. There are situations where you can rely
upon a floating-point number having exactly a certain value.
It's not much of an overstatement. How many areas are there where you
need the number
0.100000000000000005551115123125782702118158340454101562500000000000?
If I'm looking for 0.1, I will *never* (except by accident ;) say
if var == 0.1:
it'll either be <= or >=.
The following is an implementation of a well-known algorithm.
Why would you want to replace the floating point comparisons? With
what?
<snip code>
Interesting. I knew when I posted my above comment that I was ignoring
such situations. I cannot comment on the code itself as I am unaware of
the algorithm, and haven't studied numbers extensively (although I do
find them very interesting).
So while you've made your point, I believe mine still stands --
comparing floats using == to absolute numbers is almost always a mistake.
~Ethan~
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