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# Re: st: orthogonal complement of a vector

 From Stas Kolenikov To statalist@hsphsun2.harvard.edu Subject Re: st: orthogonal complement of a vector Date Sun, 19 Jun 2011 10:01:54 -0400

```The problem is ill-defined: there are infinitely many such y's
(differing in magnitude if x is two-dimensional, and differing in
direction as well if the dimension is greater than two). Which one are
you looking for?

mata
x = (1, 2, 3, 4, 5)'
y = rnormal(5,1,0,1)
y[5,1] = -( x[1..4,.]'*y[1..4,.] )/x[5,.]
x'*y
end

On Sat, Jun 18, 2011 at 5:25 PM,  <strobl@poly.polytechnique.fr> wrote:
> Dear Statalist users,
>
> does anybody know how to calculate the orthogonal complement of a vector. In
> other words, if I have a vector x, I am looking for the vector y, so that:
>
> x'*y=0
>
>
> thanks in advance for any help
>
>
> Eric
>
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--
Stas Kolenikov, also found at http://stas.kolenikov.name
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```