Re: bug in a(a<3)?

[Daniel Heiserer]

address@hidden wrote:
> 
> Daniel Heiserer wrote:
> >
> > Hi it seems that I found something really strange.
> > octave:1> a=rand(3)
> > octave:2> a(a<3)
> > octave:3> a(a<0.4))
> > For me it seems that octave makes it right for 0.4 but wrong for 3.
> 
> If you look at (a<3) it comes out all ones, while (a<0.4) with a high
> probability comes out with at least one zero.  Octave can in the latter
> case deduce that you want to select items, but in the first case it
> is ambiguous and the result depends on how you've set a certain built-in
> variable (another reply to your query gives the name of the variable).
> Your default setting obviously treats [1 1 1] as three copies of '1'
> and not as three cases of "yes, include me."

Sorry, I don't understand the philosophy behind:
'and not as three cases of "yes, include me."'
Is this a true/false 1?


For my understanding a([1 1 1 ]) should give out 
a vector 1x3 each containing a_1. Assuming
a is a matrix I would expect the first value
according the actual sorting OR an error message.

daniel



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