From help-request at octave dot org Sun Feb 13 12:24:46 2005
Subject: RE: Select elements according to the index
From: "Chen, Minyu" <mchenl at essex dot ac dot uk>
To: "Henry F. Mollet" <mollet at pacbell dot net>, "Todd Neal" <tolchz@gmail.com>
Cc: "Octave_post" <help at octave dot org>
Date: Sun, 13 Feb 2005 18:25:52 -0000

Thank you both. It was not working in 2.1.40 which came directly with my
Red Hat 9. However, as I just upgraded the package to 2.1.64, it works
perfectly.=20

Thanks,
Minyu Chen

-----Original Message-----
From: Henry F. Mollet [mailto:mollet at pacbell dot net]=20
Sent: 13 February 2005 17:30
To: Todd Neal; Chen, Minyu
Cc: Octave_post
Subject: Re: Select elements according to the index

octave:24> a=3D[1 2 3; 4 5 6]
a =3D
  1  2  3
  4  5  6
octave:25> b=3D[.1 .2 .3 .4 .5 .6 .7 .8]
b =3D
  0.10000  0.20000  0.30000  0.40000  0.50000  0.60000  0.70000  0.80000
octave:26> c=3Db(a)
c =3D
  0.10000  0.20000  0.30000
  0.40000  0.50000  0.60000
Works on
GNU Octave, version 2.1.46 (powerpc-apple-darwin6.6).
Henry

>=20
> What version of Octave are you using ?  This is from 2.1.64 Debian
Testing.
>=20
> octave:1> a=3D[1 2 3; 4 5 6];
> octave:2> b=3D[.1 .2 .3 .4 .5 .6 .7 .8];
> octave:3> c=3Db(a)
> c =3D
>=20
> 0.10000  0.20000  0.30000
> 0.40000  0.50000  0.60000
>=20
>=20
> Todd
>=20

on 2/13/05 8:04 AM, Todd Neal at tolchz at gmail dot com wrote:

> On Sun, 13 Feb 2005 13:32:25 -0000, Chen, Minyu <mchenl at essex dot ac dot uk>
wrote:
> ...
>> Suppose I have an index matrix of 2 by 3, e.g. a=3D[1 2 3; 4 5 6]
>>=20
>> And have a vector of 1 by 8, e.g. b=3D[.1 .2 .3 .4 .5 .6 .7 .8]
>>=20
>> And I want to create a matrix c of 2 by 3 (the same dimension of a),
>> with c(i,j)=3Db(a(i,j)), that's being said:
>>=20
>> c=3D[.1 .2 .3; .4 .5 .6]
>>=20
>> In matlab, as memory serves correctly, I can do it by typing:
>>=20
>> c=3Db(a)
>>=20
>> but this command in Octave will generate only a vector of 1 by 6:
>>=20
>> c=3D[.1 .4 .2 .5 .3 .6]
>>=20
>> How can I get the matrix I want?
>>=20
>> Many Thanks,
>> Minyu Chen
>=20

>=20



-------------------------------------------------------------
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
-------------------------------------------------------------