find command sometimes doesn't work in script

[Lidia Bressan]

Thanks a lot for the answer!

Just for curiosity, the equality you said works:

octave:119>  1 + 21 * 0.05 == 2.05
ans =  1
octave:120> 1 == 1
ans =  1


Lidia


Il giorno gio, 12/11/2009 alle 11.29 +0100, Jaroslav Hajek ha scritto:
> 
> 
> On Thu, Nov 12, 2009 at 11:10 AM, Lidia Bressan
> <address@hidden> wrote:
>         Sure, here I write all the information I was missing in the
>         last email.
>         
>         I use GNU Octave, version 3.2.2. I'm not sure what you mean
>         with octave
>         configuration.
>         
>         Any result:
>         
>         octave:105> any ((1:0.05:5) == 2.05)
>         ans = 0
>         
> 
> There you go. As you can see, something is wrong. I suppose the
> simpler equality
>  1 + 21 * 0.05 == 2.05
> does not hold for you either (am I right)?
> This is because numbers like 0.05 do not have an exact representation
> in the FP arithmetics. When you say 0.05, Octave actually picks the
> closest floating-point number, which is 3602879701896397 * 2^-56.
> Then, when it calculates 1 + 21 * 0.05 (and it does so even in the for
> loop), it uses this number, and the result is a tiny bit off. 
>  
> 
>         Is there a way to go around a precision issue?
> 
> Use an integer range, or don't compare for strict equality but rather
> with a tolerance.
> There is also an extension package for Octave providing fixed point
> numbers:
> http://octave.sourceforge.net/fixed/index.html
> 
> hth
> 
> 
> -- 
> RNDr. Jaroslav Hajek
> computing expert & GNU Octave developer
> Aeronautical Research and Test Institute (VZLU)
> Prague, Czech Republic
> url: www.highegg.matfyz.cz