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Topic: orthgnlizing vectors help please
Replies: 7   Last Post: Apr 22, 2013 10:39 AM

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Steven Lord

Posts: 17,945
Registered: 12/7/04
Re: orthgnlizing vectors help please
Posted: Apr 22, 2013 10:39 AM
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"A " <skgt046@ucl.ac.uk> wrote in message
> "Torsten" wrote in message <kk8or3$4eo$1@newscl01ah.mathworks.com>...
>> "Bruno Luong" <b.luong@fogale.findmycountry> wrote in message
>> <kk8o6f$2r5$1@newscl01ah.mathworks.com>...

>> > "A " <skgt046@ucl.ac.uk> wrote in message
>> > <kk8njm$1a4$1@newscl01ah.mathworks.com>...
>> >

>> > >
>> > > It did not work with me. It says that there is no matching between
>> > > the inner matrix!

>> >
>> > I bet there is no matching between what you post and what you test on
>> > your side.
>> >
>> > Bruno

>> Looks as if the OP's vectors are row vector. not column vectors.
>> Otherwise I don't see why X_orth*Y'
>> should give a scalar.
>> Best wishes
>> Torsten.

> It works with me !!
> but I thought the result Should be zero ?

In an ideal world, yes it should be exactly zero. The real world is not
ideal. In the real world, it should be close to zero for some definition of

> Is there another way or making X'*Y=0

Going to arbitrary precision arithmetic calculations using Symbolic Math
Toolbox may do what you're asking for, but you will suffer a performance hit
for doing so. Better ...

> Since I am entering these in a program that evaluate orthogonality and
> should find it equals 0

modify the program that evaluates the orthogonality to count results that
are "close enough" to 0 as orthogonal. The definition of "close enough" is
up to you.

Steve Lord
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