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Subject: Re: How to solve XA + B = 0?
Date: Thu, 2 Jul 2009 17:19:02 +0000 (UTC)
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"Tao Shen" <tshen@mathworks.com> wrote in message <h2ink4$acj$1@fred.mathworks.com>...
> Hello all,
> 
> I need to solve a equation which is XA + B =0. It is a least squares 
> problem.
> 
> The X is a 2*N matrix, A is N*2, and B is 2*2. Because A is N*2, it seems we 
> can't find its right inverse matrix but only left inverse matrix. However it 
> is not useful in this case.
> 
> Is there any method to solve this problem?

It's an under-determined system (4 equations in 2*N unknowns). You'll have to decide how  you'd like to distinguish among possibly many solutions.