RE: Filtering

[Hall, Benjamin]

Try:

x( logical(ans2) )

to tell Octave that ans2 is to be treated like an index vector -- which is
*basically* the same as Laurent's suggestion of

x( ans2==1 )



-----Original Message-----
From: Hamish Allan [mailto:address@hidden
Sent: Monday, February 28, 2005 8:24 AM
To: address@hidden
Subject: Filtering


Hi,

It seems that matrices returned by comparison operators are 'special', 
for example:

octave:1> x = [1 2 3 4 5]
x =

   1  2  3  4  5

octave:2> x > 1
ans =

   0  1  1  1  1

octave:3> x(ans)
ans =

   2  3  4  5

octave:4> ans2 = [0 1 1 1 1]
ans2 =

   0  1  1  1  1

octave:5> x(ans2)
error: invalid vector index = 0
octave:5>

Why is this? How else might I achieve what I want to do, which is:

octave:5> x((x > 1) .* (x < 4))
ans =

   2  3

octave:6>

Many thanks,
Hamish



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Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
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