Re: simple matrix problem

[taltman]

On Nov 5, 2003 at 2:47pm, Geraint Paul Bevan wrote:

g.beva >data = [ data ( : , 1 ) , detrend ( data ( : , 2 ) ) ]

Not to knit-pick, but an in-place assignment is faster than
re-allocating memory via the [...] operator:

---
octave> version
ans = 2.1.50
octave> A = rand(50,50);
octave> tic;A(:,1) = rand(50,1);toc
ans = 0.0013770
octave> tic;A = [ rand(50,1), A(:,2:50)];toc
ans = 0.0026010
---

It's almost exactly twice as fast. Sorry Geraint, this is just my
curiosity running amok! :-)

~Tomer



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