Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

Thread Subject:
Overdetermined equation system

Subject: Overdetermined equation system

From: Marcin

Date: 5 May, 2010 18:00:06

Message: 1 of 7

Hi
I'm having a lot of truble with solving overdetermined equation system in a least square sense. My equation system looks like this:

p=H*G*n

where:
 H is a 42/44 matrix
G is a 42/44 matrix
n is a 42/42 matrix

I've tried using LMFnlsq however, I haven't been successful

I would very much appreciate any help or suggestion regarding my problem

Subject: Overdetermined equation system

From: Jomar Bueyes

Date: 5 May, 2010 18:10:07

Message: 2 of 7

On May 5, 2:00 pm, "Marcin " <mkorbasiew...@gnail.com> wrote:
> Hi
> I'm having a lot of truble with solving overdetermined equation system in a least square sense. My equation system looks like this:
>
> p=H*G*n
>
> where:
>  H is a 42/44 matrix
> G is a 42/44 matrix
> n is a  42/42 matrix
>
> I've tried using LMFnlsq however, I haven't been successful
>
> I would very much appreciate any help or suggestion regarding my problem

Marcin,

Your post does not tell much detail of "I haven't been successful". Do
you get error messages, wrong results, ...?
I noticed, however, that G has the wrong size. It should be 44/42 to
be conformable to the other two matrices.

Best luck

Jomar

Subject: Overdetermined equation system

From: Matt J

Date: 5 May, 2010 18:15:22

Message: 3 of 7

"Marcin " <mkorbasiewicz@gnail.com> wrote in message <hrsbn6$8vo$1@fred.mathworks.com>...
> Hi
> I'm having a lot of truble with solving overdetermined equation system in a least square sense. My equation system looks like this:
>
> p=H*G*n
>
> where:
> H is a 42/44 matrix
> G is a 42/44 matrix
> n is a 42/42 matrix
>
> I've tried using LMFnlsq however, I haven't been successful
=============

which are the unknowns?

Subject: Overdetermined equation system

From: Roger Stafford

Date: 5 May, 2010 18:15:23

Message: 4 of 7

"Marcin " <mkorbasiewicz@gnail.com> wrote in message <hrsbn6$8vo$1@fred.mathworks.com>...
> Hi
> I'm having a lot of truble with solving overdetermined equation system in a least square sense. My equation system looks like this:
>
> p=H*G*n
>
> where:
> H is a 42/44 matrix
> G is a 42/44 matrix
> n is a 42/42 matrix
>
> I've tried using LMFnlsq however, I haven't been successful
>
> I would very much appreciate any help or suggestion regarding my problem

  Use the backslash operator, "\".

Roger Stafford

Subject: Overdetermined equation system

From: Marcin

Date: 5 May, 2010 19:06:04

Message: 5 of 7

"Roger Stafford" <ellieandrogerxyzzy@mindspring.com.invalid> wrote in message <hrscjq$9cp$1@fred.mathworks.com>...
> "Marcin " <mkorbasiewicz@gnail.com> wrote in message <hrsbn6$8vo$1@fred.mathworks.com>...
> > Hi
> > I'm having a lot of truble with solving overdetermined equation system in a least square sense. My equation system looks like this:
> >
> > p=H*G*n
> >
> > where:
> > H is a 42/44 matrix
> > G is a 42/44 matrix
> > n is a 42/42 matrix
> >
> > I've tried using LMFnlsq however, I haven't been successful
> >
> > I would very much appreciate any help or suggestion regarding my problem
>
> Use the backslash operator, "\".
>
> Roger Stafford
The unknown is p. I've made a mistake in my original massage. I is as Jomar said the matrices H and G are 44/42.

Roger I don't really see how to use the backslash operator, "\" in my case??

Subject: Overdetermined equation system

From: Matt J

Date: 5 May, 2010 19:17:09

Message: 6 of 7

"Marcin " <mkorbasiewicz@gnail.com> wrote in message <hrsfis$pia$1@fred.mathworks.com>...

> The unknown is p.
============

That can't be right. How can p be unknown when it is given by the right hand side of
this formula

p=H*G*n

and when everything on the right hand side is known?

Subject: Overdetermined equation system

From: Roger Stafford

Date: 5 May, 2010 20:40:23

Message: 7 of 7

"Marcin " <mkorbasiewicz@gnail.com> wrote in message <hrsfis$pia$1@fred.mathworks.com>...
> The unknown is p. I've made a mistake in my original massage. I is as Jomar said the matrices H and G are 44/42.
>
> Roger I don't really see how to use the backslash operator, "\" in my case??
- - - - - - - -
  If you mean that it is really n that is your unknown and p, G, and H are known, then

 n = (H*G)\p;

would give the least squares values for n (assuming it really is overdetermined!).

Roger Stafford

Tags for this Thread

No tags are associated with this thread.

What are tags?

A tag is like a keyword or category label associated with each thread. Tags make it easier for you to find threads of interest.

Anyone can tag a thread. Tags are public and visible to everyone.

Contact us