From help-request at octave dot org Sun Feb  6 15:38:04 2005
Subject: de-for-ing..
From: Gorazd Brumen <brumen at hispeed dot ch>
To: help at octave dot org
Date: Sun, 06 Feb 2005 22:42:36 +0100

Hi again,

Last time I received great suggestions from the list.
Thanks again.

I have another problem.
I wonder if the following can be done nicer:
x_init and x are two vectors. I want to get another
vector - place - that is generated by

for i = 1:lx
     place(i) = sum( x_init <= x(i) );
end

I thought of doing it this way (with kronecker products -
I am deeply into this right now, so it was the first thing
that pops up)

x_ext = kron (x, ones (n, 1))
x_init_ext = kron (ones (lx, 1), x_init )
x_tog = (x_init_ext <= x_ext)
sum(reshape (x_tog,n,lx))'

The results are the same, but the for loop is much
faster and less memory consuming. the kron solution
is preety much stupid.

Is there a better way than the for loop?

Regards,

-- 
Gorazd Brumen
Mail: brumen at isb dot unizh dot ch
WWW: http://valjhun.fmf.uni-lj.si/~brumen
PGP: Key at http://pgp.mit.edu, ID BCC93240



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