From: "trans.  (T. Onoma)" <transami@...>
Date: 2004-10-16T02:27:51+09:00
Subject: Re: Rounding to X digits

On Friday 15 October 2004 12:02 pm, Markus wrote:
|      Peeling one layer of the onion, they differ because:
|
| irb(main):033:0> printf "%20.15f",(134.45 * (1.0/0.1))
| 1344.500000000000000=> nil
| irb(main):034:0> printf "%20.15f",(134.45/0.1)
| 1344.499999999999773=> nil

That isn't too... er... reassuring.

| I suppose this is not unexpected (my mama warned me 'bout floats) but it
| is a little unexpected--no, I'm wrong, 1/5 is a repeating decimal base
| 2, so it's perfectly expected. 

Expected, really? I'm not all that familiar with floating point standards, but 
I would have though this kind of thing would have been worked out long ago. 
It's a pretty substantiate miscalculation. --And the fact that simply using 
'*(1.0/0.1)' fixes it, makes me think so even more.


T.