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Posted to user@commons.apache.org by petitout <pe...@gmail.com> on 2012/03/16 17:01:48 UTC

[commons math] - complex matrix inversion

Hi,

First, congratulations for all your work !

I would like to know if there is a mean to inverse a matrix containing
complex numbers using you library ?
If not, do you know if it will be availble in a future release ?
If not, do you know how can I do ?

Thanks a lot,

Best regards,

Julien

Re: [commons math] - complex matrix inversion

Posted by petitout <pe...@gmail.com>.

Thanks for your answer Ted!

my question now is : is there any solver which handles complex matrix in
commons math?

thanks!
Le 16 mars 2012 18:39, "Ted Dunning" <te...@gmail.com> a écrit :

> If you really must do this, use a solver and feed it the identity matrix.
>  That is, given the matrix A, solve the matrix system AX = I
>
> Any solver that handles complex matrix right hand sides will do this for
> you.  Iterative calls to a solver with successive columns of I can also be
> used to fill in columns of X.
>
> But I strongly recommend you rethink the approach.  There are very few
> cases were inverting a matrix is a good idea.
>
> On Fri, Mar 16, 2012 at 9:01 AM, petitout <pe...@gmail.com> wrote:
>
>> Hi,
>>
>> First, congratulations for all your work !
>>
>> I would like to know if there is a mean to inverse a matrix containing
>> complex numbers using you library ?
>> If not, do you know if it will be availble in a future release ?
>> If not, do you know how can I do ?
>>
>> Thanks a lot,
>>
>> Best regards,
>>
>> Julien
>>
>
>

Re: [commons math] - complex matrix inversion

Posted by Ted Dunning <te...@gmail.com>.

Modulo certain typos.

On Fri, Mar 16, 2012 at 10:52 AM, Luc Maisonobe <Lu...@free.fr>wrote:

> In this case, you can create a FiledMatrix<Complex> using
> MatrixUtils.createFildMatrix factory method (or just use a constructor
> of the field matrix class you prefer). Then use
> FieldLUDecomposition<Complex> to get the solver.
>

Re: [commons math] - complex matrix inversion

Posted by Luc Maisonobe <Lu...@free.fr>.

Le 16/03/2012 18:39, Ted Dunning a écrit :
> If you really must do this, use a solver and feed it the identity matrix.
>  That is, given the matrix A, solve the matrix system AX = I
> 
> Any solver that handles complex matrix right hand sides will do this for
> you.  Iterative calls to a solver with successive columns of I can also be
> used to fill in columns of X.

In this case, you can create a FiledMatrix<Complex> using
MatrixUtils.createFildMatrix factory method (or just use a constructor
of the field matrix class you prefer). Then use
FieldLUDecomposition<Complex> to get the solver.

> 
> But I strongly recommend you rethink the approach.  There are very few
> cases were inverting a matrix is a good idea.

I strongly agree with Ted here, direct inversion is often not the better
approach.

Luc

> 
> On Fri, Mar 16, 2012 at 9:01 AM, petitout <pe...@gmail.com> wrote:
> 
>> Hi,
>>
>> First, congratulations for all your work !
>>
>> I would like to know if there is a mean to inverse a matrix containing
>> complex numbers using you library ?
>> If not, do you know if it will be availble in a future release ?
>> If not, do you know how can I do ?
>>
>> Thanks a lot,
>>
>> Best regards,
>>
>> Julien
>>
> 


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Re: [commons math] - complex matrix inversion

Posted by Ted Dunning <te...@gmail.com>.

If you really must do this, use a solver and feed it the identity matrix.
 That is, given the matrix A, solve the matrix system AX = I

Any solver that handles complex matrix right hand sides will do this for
you.  Iterative calls to a solver with successive columns of I can also be
used to fill in columns of X.

But I strongly recommend you rethink the approach.  There are very few
cases were inverting a matrix is a good idea.

On Fri, Mar 16, 2012 at 9:01 AM, petitout <pe...@gmail.com> wrote:

> Hi,
>
> First, congratulations for all your work !
>
> I would like to know if there is a mean to inverse a matrix containing
> complex numbers using you library ?
> If not, do you know if it will be availble in a future release ?
> If not, do you know how can I do ?
>
> Thanks a lot,
>
> Best regards,
>
> Julien
>