From help-request at octave dot org Fri Feb 18 11:37:46 2005
Subject: Re: C++ using Octave headers, mkoctfile
From: Francesco Potorti` <Potorti at isti dot cnr dot it>
To: sct at ucsd dot edu
CC: help at octave dot org
Date: Fri, 18 Feb 2005 18:40:44 +0100

>I have learned how to generate random variables -- a big step.  But I'm
>currently stuck on building a complex matrix (or returning a complex
>number).  For example, what would the C++ code be to generate:
>
>n=[0:29]';
>W=zeros(30,30);
>for k=1:30
> W(:,k)=exp(j*2*pi*k*n/30);
>end

Perhaps, before trying to produce C++ code, you should try to learn how
to use Octave's vector abilities at their best.  For example, the code
you wrote can be vectorialised as:

N=30; W=exp(j*2*pi*[0:N-1]'*[1:N]/N);

and it runs faster.

-- 
Francesco Potort́ (ricercatore)        Voice: +39 050 315 3058 (op.2111)
ISTI - Area della ricerca CNR          Fax:   +39 050 313 8091
via G. Moruzzi 1, I-56124 Pisa         Email: Potorti at isti dot cnr dot it
Web: http://fly.isti.cnr.it/           Key:   fly.isti.cnr.it/public.key



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