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Re: Is this a numerical problem?
From: |
Lukas Reichlin |
Subject: |
Re: Is this a numerical problem? |
Date: |
Thu, 19 Aug 2010 11:32:45 +0200 |
Hi Jaroslav
Thanks for your quick reply. # a < -4 is meant as a comment about what I've
learned at elementary school ;-) -4.0000...001 is smaller than -4 while
-3.99999… is greater than -4. Anything different from that would wreck my world
view, but hey, I'm willing to learn something new.
octave:18> a = 10 * rem (-12/5, 1)
a = -4.0000
octave:19> a < -4
ans = 0 # I'm expecting 1 here
octave:20> -4.001 < -4
ans = 1 # I agree :-)
Best Regards,
Lukas
BTW:
octave:22> a <= -4
ans = 0
On 19.08.2010, at 10:51, Jaroslav Hajek wrote:
> On Thu, Aug 19, 2010 at 10:39 AM, Lukas Reichlin
> <address@hidden> wrote:
>> Dear Octave community
>>
>> I'm using Octave 3.2.4 from MacPorts on MacOSX 10.6.4 running on an Intel
>> Core 2 Duo. I noticed a behaviour which seems strange to me. Does someone
>> have a good explanation for the results below?
>>
>> octave:60> a = (10 * rem (-12/5, 1))
>> a = -4.00000000000000 # a < -4
>
>
> Stop right there and ask yourself where you did that # a < -4 from.
> Surely you've tested it, right? :D
>
> --
> RNDr. Jaroslav Hajek, PhD
> computing expert & GNU Octave developer
> Aeronautical Research and Test Institute (VZLU)
> Prague, Czech Republic
> url: www.highegg.matfyz.cz
- Is this a numerical problem?, Lukas Reichlin, 2010/08/19
- Re: Is this a numerical problem?, Jaroslav Hajek, 2010/08/19
- Re: Is this a numerical problem?,
Lukas Reichlin <=
- Message not available
- Re: Is this a numerical problem?, Jaroslav Hajek, 2010/08/19
- Re: Is this a numerical problem?, Lukas Reichlin, 2010/08/19
- Re: Is this a numerical problem?, Sergei Steshenko, 2010/08/19
- Re: Is this a numerical problem?, Jaroslav Hajek, 2010/08/19
- Re: Is this a numerical problem?, Miguel Bazdresch, 2010/08/19
- Re: Is this a numerical problem?, Lukas Reichlin, 2010/08/19
- Re: Is this a numerical problem?, Jaroslav Hajek, 2010/08/19
- Re: Is this a numerical problem?, Lukas Reichlin, 2010/08/19