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9 messages
9 total messages Started by Craig Armour Sun, 20 Jun 1999 00:00
Singular Value Decomposition
#1226
Author: Craig Armour
Date: Sun, 20 Jun 1999 00:00
23 lines
1582 bytes
Hi,

I need to write a paper on the use of Singular value Decomposition in
numerical Algebra for numerical maths.  The main problem I'm having is
finding a paper or the sort which describes the svd w.r.t other
algorithms interms of performance and various problems.  

I realise SVD's are great for overconditioned problmes, but how are they
better than say a QR factorization.  As far as I can figure, alot of
algorithms use QR and the sort to compute the svd.  what about w.r.t
eigen value problems.

In short, I have a lot of info telling me that SVD's are great for
overconditioned systems and least squares but not much else.  Is this
the only use of SVD's? for least squares style problems???

Cheers
Craig
-- 
Craig Armour                    c.armour@cltr.uq.edu.au
System Administrator             Joyce Ackroyd Building
Language Lab, University of Queensland   phone 33656916
Comments are my own and not of my employer
Re: Singular Value Decomposition
#1227
Author: Peter Schroeder
Date: Sun, 20 Jun 1999 00:00
5 lines
851 bytes
Hi Craig,
the book 
"Matrix Computations" by Golub and Van Loan 
is a good reference.
Peter
Re: Singular Value Decomposition
#1228
Author: Bernard Danloy
Date: Mon, 21 Jun 1999 00:00
25 lines
1828 bytes
In article <376C787E.939C192B@kings.uq.edu.au>, c.armour@uq.net.au wrote๏ฟฝ:

: Hi,
: 
: I need to write a paper on the use of Singular value Decomposition in
: numerical Algebra for numerical maths.  The main problem I'm having is
: finding a paper or the sort which describes the svd w.r.t other
: algorithms interms of performance and various problems.  
: 
: I realise SVD's are great for overconditioned problmes, but how are they
: better than say a QR factorization.  As far as I can figure, alot of
: algorithms use QR and the sort to compute the svd.  what about w.r.t
: eigen value problems.
: 
: In short, I have a lot of info telling me that SVD's are great for
: overconditioned systems and least squares but not much else.  Is this
: the only use of SVD's? for least squares style problems???
: 

Not many people know it but all orthogonal polynomials satisfy coupled
2-terms recurrences, so that their zeros are related with the singular
values of a bidiagonal matrix ; SVD is therefore an essential tool in
the numerical construction of Gaussian quadratures.

Bernard Danloy
Re: Singular Value Decomposition
#1229
Author: Kevin G. Rhoads
Date: Mon, 21 Jun 1999 00:00
11 lines
931 bytes
In matrix inversion, nearly singular values result in rapid 
loss of precision in machine calculation.  The SVD approach
has been adapted to improving accuracy and precision in
machine inversion of nearly-singular matrices.

So you have a whole arena of machine-computation literature
to check also.
-- 
Kevin G. Rhoads, Ph.D. (Linearity is a convenient fiction.)
T_Rhoads@NO_SPAM.MSN.com
krhoads@NO_SPAM.cmpnetmail.com
Re: Singular Value Decomposition
#1230
Author: Louis M. Pecora
Date: Mon, 21 Jun 1999 00:00
25 lines
1949 bytes
In article <danloy-2106991346450001@quadra.anma.ucl.ac.be>,
danloy@anma.ucl.ac.be (Bernard Danloy) wrote:

 > Not many people know it but all orthogonal polynomials satisfy coupled
> 2-terms recurrences, so that their zeros are related with the singular
> values of a bidiagonal matrix ;

Hi Bernard,

This is very interesting.  Can you point to a reference where I can read
more?  Thanks.

-- 
Louis M. Pecora
pecora@anvil.nrl.navy.mil
 == My views and opinions are not those of the U.S. Navy. ==
 == No Spamming or Soliciting -- both are illegal at this site ==
--------------------------------------------------------------------- 
  Check out our Nonlinear Web site: http://chaos-mac.nrl.navy.mil/
--------------------------------------------------------------------
------------------------------------------------------------------------
 * The 5th Experimental Chaos Conference June 1999.
Check it out at http://www.physics.gatech.edu/ecc5/#proceedings
 * The 4th Experimental Chaos Conference Sessions & Abstracts Online: http://natasha.umsl.edu/Exp_Chaos4, proceedings now available.
---------------------------------------------------------------------
Re: Singular Value Decomposition
#1231
Author: Bernard Danloy
Date: Mon, 21 Jun 1999 00:00
29 lines
1931 bytes
In article <pecora-2106990936270001@pecora7600.nrl.navy.mil>,
pecora@zoltar.nrl.navy.mil (Louis M. Pecora) wrote ๏ฟฝ:

: In article <danloy-2106991346450001@quadra.anma.ucl.ac.be>,
: danloy@anma.ucl.ac.be (Bernard Danloy) wrote:
: 
:  > Not many people know it but all orthogonal polynomials satisfy coupled
: > 2-terms recurrences, so that their zeros are related with the singular
: > values of a bidiagonal matrix ;
: 
: Hi Bernard,
: 
: This is very interesting.  Can you point to a reference where I can read
: more?  Thanks.
 ---------------------------------------------------------------------

Sorry, i don't have many pointers ...

The coupled recurrences are the system (2.6) in a paper of mine in Math.
Comp. vol. 27 ( 1973 ) p. 863

Rewriting the system by means of a bidiagonal matrix ( the singular values
of which are the shifted zeroes of the n-th orthogonal polynomial ) is a
10-years old unpublished result ...

But recently, similar results have been obtained independently by Dirk
Laurie and i believe you should find something in a coming issue of JCAM.

Bernard Danloy
Re: Singular Value Decomposition
#1232
Author: Louis M. Pecora
Date: Mon, 21 Jun 1999 00:00
36 lines
2483 bytes
In article <danloy-2106991659300001@quadra.anma.ucl.ac.be>,
danloy@anma.ucl.ac.be (Bernard Danloy) wrote:

> : Hi Bernard,
> : 
> : This is very interesting.  Can you point to a reference where I can read
> : more?  Thanks.
>  ---------------------------------------------------------------------
> 
> Sorry, i don't have many pointers ...
> 
> The coupled recurrences are the system (2.6) in a paper of mine in Math.
> Comp. vol. 27 ( 1973 ) p. 863
> 
> Rewriting the system by means of a bidiagonal matrix ( the singular values
> of which are the shifted zeroes of the n-th orthogonal polynomial ) is a
> 10-years old unpublished result ...
> 
> But recently, similar results have been obtained independently by Dirk
> Laurie and i believe you should find something in a coming issue of JCAM.

OK.  Will check it.

-- 
Louis M. Pecora
pecora@anvil.nrl.navy.mil
 == My views and opinions are not those of the U.S. Navy. ==
 == No Spamming or Soliciting -- both are illegal at this site ==
--------------------------------------------------------------------- 
  Check out our Nonlinear Web site: http://chaos-mac.nrl.navy.mil/
--------------------------------------------------------------------
------------------------------------------------------------------------
 * The 5th Experimental Chaos Conference June 1999.
Check it out at http://www.physics.gatech.edu/ecc5/#proceedings
 * The 4th Experimental Chaos Conference Sessions & Abstracts Online: http://natasha.umsl.edu/Exp_Chaos4, proceedings now available.
---------------------------------------------------------------------
Re: Singular Value Decomposition
#1233
Author: Robin Becker
Date: Mon, 21 Jun 1999 00:00
23 lines
1590 bytes
In article <376C787E.939C192B@kings.uq.edu.au>, Craig Armour
<c.armour@kings.uq.edu.au> writes
>Hi,
>
>I need to write a paper on the use of Singular value Decomposition in
>numerical Algebra for numerical maths.  The main problem I'm having is
>finding a paper or the sort which describes the svd w.r.t other
>algorithms interms of performance and various problems.  
>
>I realise SVD's are great for overconditioned problmes, but how are they
>better than say a QR factorization.  As far as I can figure, alot of
>algorithms use QR and the sort to compute the svd.  what about w.r.t
>eigen value problems.
>
>In short, I have a lot of info telling me that SVD's are great for
>overconditioned systems and least squares but not much else.  Is this
>the only use of SVD's? for least squares style problems???
>
>Cheers
>Craig

-- 
Robin Becker
Re: Singular Value Decomposition
#1234
Author: Robin Becker
Date: Tue, 22 Jun 1999 00:00
26 lines
1821 bytes
In article <8mtuqCAENrb3EwoQ@jessikat.demon.co.uk>, Robin Becker
<robin@jessikat.demon.co.uk> writes
>In article <376C787E.939C192B@kings.uq.edu.au>, Craig Armour
><c.armour@kings.uq.edu.au> writes
>>Hi,
>>
>>I need to write a paper on the use of Singular value Decomposition in
>>numerical Algebra for numerical maths.  The main problem I'm having is
>>finding a paper or the sort which describes the svd w.r.t other
>>algorithms interms of performance and various problems.  
>>
>>I realise SVD's are great for overconditioned problmes, but how are they
>>better than say a QR factorization.  As far as I can figure, alot of
>>algorithms use QR and the sort to compute the svd.  what about w.r.t
>>eigen value problems.
>>
>>In short, I have a lot of info telling me that SVD's are great for
>>overconditioned systems and least squares but not much else.  Is this
>>the only use of SVD's? for least squares style problems???
>>
>>Cheers
>>Craig
>
sorry for the spurious post, maybe I've got some kind of problem.
-- 
Robin Becker
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