comp.lang.idl-pvwave archive: archive

Home » Public Forums » archive » Re: Matrix rank

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: Matrix rank [message #57533]

Fri, 14 December 2007 09:26

d.poreh
Messages: 406
Registered: October 2007

Senior Member

On Dec 14, 5:28 pm, Vince Hradil <hrad...@yahoo.com> wrote:
> On Dec 14, 9:42 am, Wox <nom...@hotmail.com> wrote:
>
>
>
>
>
>> On Fri, 14 Dec 2007 06:35:11 -0800 (PST), Vince Hradil
>
>> <hrad...@yahoo.com> wrote:
>>> IDL can do SVD, can you get the rank from that? Look up SVDC in the
>>> docs.
>
>> I could do this, but maybe there's a better way?
>
>> ; A: integers
>> ; B: floats
>> A = [[ 0,0,1], $
>> [ 0,1,0], $
>> [ 0,0,0]]
>> B = [0.25,0.5,1]
>
>> ; Decompose A
>> SVDC, A, W, U, V
>> ; Solve A.X=B
>> X=SVSOL(U, W, V, B)
>
>> ; Check
>> B2=A##X
>> ind=where(total(abs(A),1,/pres) ne 0)
>
>> if array_equal(B[ind],B2[ind]) then print,X
>
> Well, w contains the singular values, the number of these that are non-
> zero will be the rank:
> idx = where(w ne 0, rank)
> print, rank
> 2
>
> Does anyone else read the Help??????- Hide quoted text -
>
> - Show quoted text -

Huuum!!! what about NORM?

Report message to a moderator

[Message index]

		Re: Matrix rank By: d.poreh on Fri, 14 December 2007 09:26
		Re: Matrix rank By: d.poreh on Fri, 14 December 2007 09:19
		Re: Matrix rank By: Vince Hradil on Fri, 14 December 2007 09:17
		Re: Matrix rank By: David Fanning on Fri, 14 December 2007 08:35
		Re: Matrix rank By: Vince Hradil on Fri, 14 December 2007 08:28
		Re: Matrix rank By: David Fanning on Fri, 14 December 2007 07:57
		Re: Matrix rank By: Wox on Fri, 14 December 2007 07:44
		Re: Matrix rank By: Wox on Fri, 14 December 2007 07:42
		Re: Matrix rank By: d.poreh on Fri, 14 December 2007 07:41
		Re: Matrix rank By: Wox on Fri, 14 December 2007 07:25
		Re: Matrix rank By: Vince Hradil on Fri, 14 December 2007 06:35
		Re: Matrix rank By: Steve Eddins on Fri, 14 December 2007 10:06
		Re: Matrix rank By: Vince Hradil on Fri, 14 December 2007 09:49

Previous Topic:	Off Topic Computer Post
Next Topic:	Compiling error in Envi batch mode

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Thu Oct 09 23:34:44 PDT 2025

Total time taken to generate the page: 0.15684 seconds