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From: "Steven Lord" <slord@mathworks.com>
Newsgroups: comp.soft-sys.matlab
Subject: Re: pinv
Date: Thu, 5 Nov 2009 10:31:54 -0500
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"munir" <munirpansare@gmail.com> wrote in message 
news:19fa6366-f064-4679-824f-fabe56ce387c@u36g2000prn.googlegroups.com...
> On Nov 5, 4:18 am, "ade77 " <ade1...@gmail.com> wrote:
> > > Error in ==> pinv at 29
> > > [U,S,V] = svd(A,0);
> >
> > > Error in ==> Untitled17 at 238
> > > o = pinv(l)
> >
> > can you include the matrix in question
>
> this is the type of matrix which is singular.it is much smaller than
> what i ll be using.
> keeassembly =
> [ 250*pi*ep33s,            0, 250*pi*ep33s,            0]
> [            0, 250*pi*ep33a,            0, 250*pi*ep33a]
> [ 250*pi*ep33s,            0, 250*pi*ep33s,            0]
> [            0, 250*pi*ep33a,            0, 250*pi*ep33a]

You can't invert this matrix; rows 1 and 3 are identical, as are rows 2 and 
4.  This means it's not full rank and so has no inverse.  PINV won't help 
either -- it's intended for numeric matrices, not symbolic matrices.

If you're trying to invert the matrix in order to solve a system of 
equations, DON'T, repeat DO NOT INVERT IT.  Instead use backslash (\) to 
solve the system directly.

-- 
Steve Lord
slord@mathworks.com
comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ