FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups 
 ProfileProfile   PreferencesPreferences   Log in to check your private messagesLog in to check your private messages   Log inLog in 
Forum index » Science and Technology » Math » num-analysis
convergence of QR-algorithm
Post new topic   Reply to topic Page 18 of 19 [276 Posts] View previous topic :: View next topic
Goto page:  Previous  1, 2, 3, ..., 16, 17, 18, 19 Next
Author Message
Art Kendall
science forum beginner


Joined: 16 Jun 2005
Posts: 9

PostPosted: Wed Apr 05, 2006 1:38 am    Post subject: Re: multidimensional scaling clustering Reply with quote

You're welcome.

Art

bird wrote:
Quote:
Ark,

Thank you so much for your help. I will keep looking
the links you provide. Thank you again.

-Kevin

"Art Kendall" <Arthur.Kendall@verizon.net> wrote:

Doug Carroll and colleagues at Bell labs created extensions to the
single matrix MDS (e.g., Joe Kruskal).
George xxxx developed a method that found clusters and dimensions on the
same run.

The Classification Society Of North America is for people from all kinds
of disciplines who are interested in MDS, clustering, etc. Biologists,
Psychologists, statisticians, astronomers, zoologists, computer and
information scientists, etc.

If you go to
http://www.classification-society.org/csna/csna.html
to learn about the society
click < mailing list > on the bottom left of the page or go to

http://www.classification-society.org/csna/lists.html#class-l
to learn about class-l

This would be a good place to pose your questions.

Art
Art@DrKendall.org
Social Research Consultants


bird wrote:

Thank you for your help. I read some books and I think I see
some of your points now. I have just one more question.

Suppose I have n objects, each has m features, then I actually
have a matrix A(nxm). I want to use MDS to reduce the features
to a p dimensional space, that's say I want a matrix B(nxp).
The final configuration attained by MDS is actually a transformation
T(mxp) telling me how to transform A to B. Is it right? Since
it is a nonliear transformation, does B equal A x T?






Back to top
singapore_hadalamolaya
science forum beginner


Joined: 11 Apr 2006
Posts: 1

PostPosted: Tue Apr 11, 2006 2:14 pm    Post subject: Re: JOHN CHIPMAN OWNER OF CHIPMAN RELOCATIONS UNITED VAN LINES MAYFLOWER CATON MOVING & STORAGE likes to make many harassing/harassment phone calls Reply with quote

arewehavingfunyetyes wrote:
Quote:
JOHN CHIPMAN OWNER OF CHIPMAN RELOCATIONS UNITED VAN LINES MAYFLOWER
CATON MOVING & STORAGE likes to make many harassing/harassment phone
calls
JOHN CHIPMAN OWNER OF CHIPMAN UNITED VAN LINES likes
to make many harassing/harassment phone calls to people and the
old man sounds like he is off his meds he says my name is
JOHN CHIPMAN OWNER OF CHIPMAN UNITED VAN LINES
and i would like to buy you a cup of tea. you can hear the
many harassing/harassment phone calls he is making from
510-337- & 510-337- @ http://tinyurl.com/pe67o
United Van Lines Agent,Concord, CA 94520
Chipman Relocations, Alameda, CA 94501
moving boxes
California Movers storage
zoominfo.com

John Wants To Buy This Guy A Denny's $1.99 Breakfast Special
http://www3.youtube.com/profile_videos?user=arewehavingfunyet
Back to top
David L. Wilson
science forum beginner


Joined: 31 May 2005
Posts: 37

PostPosted: Fri Apr 14, 2006 1:17 am    Post subject: Re: Free math software Reply with quote

"Evgeny Turchyn" <evgturchin@narod.ru> wrote in message
news:Xns97A440B26CF5Ftvn47ateleportcom@195.248.191.68...
Quote:
Hello, All!
Can anyone recommend a good free math software for Windows
with abilities compatible with those of Scilab or Maple - i.e
having all basic mathematical capabilities: integration,
plotting, built-in programming language etc. ? (Please do not
offer Scilab.)
What can one say about R for Windows? Is it good at such
problems as numeric integrating, for instance?

R is designed for statistics work (it is an implementation of the S
statistics language).
I suggest you consider Maxima for what you are interested in doing.
http://maxima.sourceforge.net/
Back to top
Rusty
science forum addict


Joined: 30 Apr 2005
Posts: 70

PostPosted: Sat Apr 15, 2006 9:03 am    Post subject: Re: Discover Medieval Romania /Vlad the Impaler/Dracula/ /www.medievaltours.ro Reply with quote

Medieval Tours wrote:
Quote:
br


div align="center"><a
href="http://www.medievaltours.ro/en/about.php"><span


my browser never did support html

john2
Back to top
David Langevin
science forum beginner


Joined: 16 Aug 2005
Posts: 9

PostPosted: Fri May 05, 2006 1:00 am    Post subject: Re: not positive-definite covariance matrix Reply with quote

Hi,

When I look at your eigenvalues, I see one who is negative, and it mean that your matrix is not positive definite.

At this point you have three way to solve your problem:

1) Check your data to see if you cannot pertubate one entry in your matrix to have a positive definite one

2) Or you can use hypersphere decomposition from your not positive definite matrix and obtain one who is close to your matrix but positive definite (see Monte Carlo methods in finance, Jackel for detail, chapter 6)

3) Or you can use spectral decomposition from your not positive definite matrix and obtain one who is close to your matrix but positive definite (see Monte Carlo methods in finance, Jackel for detail, chapter 6)

I prefer spectral decomposition, because it more handy and easy to use than spectral decompostion. Also you don't have to solve an optimization problem.

DL
Back to top
Roger Stafford
science forum beginner


Joined: 14 Jun 2005
Posts: 5

PostPosted: Fri May 05, 2006 7:56 pm    Post subject: Re: not positive-definite covariance matrix Reply with quote

In article
<ellieandrogerxyzzy-0505061242480001@dialup-4.232.228.189.dial1.losangeles1.level3.net>,
ellieandrogerxyzzy@mindspring.com.invalid (Roger Stafford) wrote:

Quote:
I am very curious about your matrix d. You describe it as, "d is
...
-----

Sorry about the duplications. They were not intentional.

(Remove "xyzzy" and ".invalid" to send me email.)
Roger Stafford
Back to top
Gottfried Helms
science forum Guru


Joined: 24 Mar 2005
Posts: 301

PostPosted: Fri May 05, 2006 8:14 pm    Post subject: Re: not positive-definite covariance matrix Reply with quote

ANother approach, besides the already given ones,
may be a SVD-decomposition. Since it is a covariance,
it is symmetric and

M = S D T = S D S'

where D is diagonal.
Then you could inspect D and see, whether you may
apply rounding to zero for very small negative D.
After that the cholesky-decomposition is

C = S * D^(1/2)

and

M = C * C'

THis way you may have more control over the numerical
problems, and I think, Matlab should provide the tools
to deal with this problem sensibly.

Gottfried Helms
Back to top
Jean-Marc Gulliet
science forum beginner


Joined: 28 May 2005
Posts: 38

PostPosted: Sun May 21, 2006 3:00 pm    Post subject: Re: Trig identity Reply with quote

Andrew Poelstra wrote:
Quote:
On 2006-05-20, Kaimbridge <Kaimbridge@gmail.com> wrote:
Borked Pseudo Mailed wrote:
1-cos(x)
-------- = tan(x/2)^2
1+cos(x)

1-cos(x)^2
---------- = ?????
1+cos(x)^2

Does anyone know what function this reduces to?
I presume you mean a single function, in which case I don't think there
is one.
However, besides the ones that others have pointed out, some more
equivalencies are:

sin(x)^2 .5*sin(x)^2 2*sin(.5*x)^2*cos(.5*x)^2
------------ = --------------- = -----------------------------,
2 - sin(x)^2 1 - .5*sin(x)^2 1 - 2*sin(.5*x)^2*cos(.5*x)^2

2
= -------------------------;
tan(.5*x)^2 + cot(.5*x)^2


~Kaimbridge~

Here's an equivilancy with the benifit of being easy to type:
(cos(x) - 1)(cos(x) + 1)
--------------------------
-(cos(x) - i)(cos(x) + i)

Here is what I get with Mathematica 5.2


In[1]:=
TrigReduce[(1 - Cos[x]^2)/(1 + Cos[x]^2)]

Out[1]=
1 - Cos[2 x]
------------
3 + Cos[2 x]

HTH,
Jean-Marc
Back to top
Tony Lance
science forum beginner


Joined: 18 May 2005
Posts: 30

PostPosted: Mon May 22, 2006 12:09 pm    Post subject: Re: Big Bertha Thing blogs Reply with quote

Big Bertha Thing letter
Cosmic Ray Series
Possible Real World System Constructs
http://web.onetel.com/~tonylance/letter.html
4K Web Page
Astrophysics net ring Access site
Newsgroup Reviews including sci.physics.particle

Letter to a friend explaining Pastures and quest.

From Pastures Software Package Documentation.
(Particle Structure Results Program in Fortran 77.)
Sub-atomic Mesons, Baryons and Leptons Classification System.
(C) Copyright Tony Lance 1997
Distribute complete and free of charge to comply.

Big Bertha Thing folder

Keep busy in your mailbox and put all postings
in a PIP Research folder for safe-keeping in perpetuity,
every night.

Part of your chores would be to read each missive,
subject by subject. Answer it, in a weekly PIP Research
Newsletter or not, as the case may be, which would again,
go rapidly from the mailbox to the folder.

(C) Copyright Tony Lance 1997.
To comply with my copyright,
please distribute complete and free of charge.

Tony Lance
tonylance@webandmail.co.uk


Big Bertha Thing debit

UK big banks have now made debit cards mandatory.
1. Every cheque book has a debit card.
2. You do not sign agreement for debit card.
3. Lost or stolen cards must be cancelled.
4. Insure debit cards for 1000 pounds sterling.
5. For every 8 pounds loss charged to the customer, the bank can
lend 92 pounds. (Multiplier)
6. Cheque guarantee card included.
7. Cash Card included.
8. Phantom withdrawals included.
9. 50 pounds cashback at supermarkets.
10. 250 pounds 'Hole-in-the-wall' withdrawals.
11. 100 pounds Post Office and bank withdrawals.
12. How do you prove that you have cut the card up and disposed of it?
13. How do you prove that you did not use it before destruction?
14. Cut the card up and give to your solicitor or third party for
safe-keeping. (Escrow)
15. The survival of the banks depends on putting customers to the
sword. (Barbaric) Obviously not all customers, just enough.
16. Unauthorized access to debit card accounts, includes both
criminals and bank insiders, which seem to be synonymous.
17. Authorized access to debit card accounts, includes bank
insiders, grazing on the customers like milk cows, in their
official capacity, as per job description.
18. You no longer need to prove this in a court of law, since it is
endemic and ubiquitous. (Common knowledge) Case law sufficient
for class action.
Back to top
astanoff@yahoo.fr
science forum beginner


Joined: 21 Oct 2005
Posts: 17

PostPosted: Fri Jun 09, 2006 6:27 am    Post subject: Re: Normal distribution function with skew and kurtosis Reply with quote

About the skew-normal distribution,
you can have a look at :

http://www.bus.lsu.edu/economics/faculty/chill/personal/aie/DeLuca.pdf


v.a.
Back to top
J.V.Ashby
science forum beginner


Joined: 10 Jun 2005
Posts: 12

PostPosted: Thu Jun 15, 2006 7:23 am    Post subject: Re: ANNOUNCE: comp.soft-sys.octave has been created Reply with quote

This may be of interest to some here.

john


The Big-8 Management Board wrote:

Quote:
The Big-8 Management Board has voted to create comp.soft-syst.octave.
The group was created on 12 Jun 2006.


NEWSGROUPS LINE:

comp.soft-sys.octave GNU Octave, language for numerical
computations.


CHARTER: comp.soft-sys.octave

General GNU Octave questions and its application to specific fields
such as digital signal processing, digital communications, medical
imaging, etc., as well as development issues such as bugs, fixes,
workarounds, etc., in the main Octave kernel as well as developer- and
user-supplied scripts (.m files) which extend Octave's functionality.

The general issues include:

* Addressing new user queries.
* Exchange of source code in public domain, especially .m scripts.
* Addressing the applications of GNU Octave in various fields.

Usage specific in fields like Signal Processing:

* Exchange of public domain source code to strengthen the signal
processing part of GNU Octave.
* Addressing the beginner to advanced queries regarding various
signal
processing related function available with GNU Octave, as built-in
or as separate packages.

Commercial Postings

Commercial advertising related to Octave from software vendors,
publishers, etc. will be permitted in a very limited fashion.

Unwelcome posts

Flames and other non-constructive criticism are harmful when directed
to new readers. The octave group is meant to be a friendlier place on
the net for beginners, intermediate, advanced users. Flames and other
non-constructive criticism aimed at those seeking help are unwelcome.

END CHARTER.


PROPONENT:

Himanshu Singh Chauhan <hs.chauhan@gmail.com


HISTORY:

2006-06-12 Group created.
2006-06-09 Vote ends; group will be created on 12 Jun 2006.
2006-06-02 Third RFD/last-call-for-comments posted.
2006-05-20 Second RFD submitted; reformatted by Tim Skirvin.
2006-05-18 Added several more newsgroups.
2006-03-15 Reformatted by Tim Skirvin for posting as an RFD.
2006-03-14 Submitted by Himanshu Singh Chauhan.
Back to top
Himanshu Chauhan
science forum beginner


Joined: 15 Jun 2006
Posts: 2

PostPosted: Thu Jun 15, 2006 9:51 am    Post subject: Re: ANNOUNCE: comp.soft-sys.octave has been created Reply with quote

J.V.Ashby wrote:
Quote:
This may be of interest to some here.

john



This group hasn't been added by google yet. I am, atleast, waiting for
them to do so.

I wasn't aware of this group earlier so I didn't cross post the RFDs
here. I am sorry for that.

--
----------------------------------------
Himanshu Chauhan
MCA (Final Year)
I.G. National Open University
Jaipur (India)

Mobile:(+91)-(98292)-(92757)
Web: http://members.lycos.co.uk/hschauhan
Email: hs.chauhan@gmail.com

"Education is what remains after one
has forgotten everything he learned
in school." -- A. Einstein.
----------------------------------------
Back to top
Martin Eisenberg
science forum beginner


Joined: 11 May 2005
Posts: 28

PostPosted: Thu Jun 15, 2006 2:00 pm    Post subject: Re: ANNOUNCE: comp.soft-sys.octave has been created Reply with quote

Himanshu Chauhan wrote:

Quote:
This group hasn't been added by google yet. I am, atleast,
waiting for them to do so.

What do you mean?
http://groups.google.com/group/sci.math.num-analysis


Martin

--
Quidquid latine scriptum sit, altum viditur.
Back to top
Jean-Claude Arbaut
science forum Guru


Joined: 13 Jun 2005
Posts: 573

PostPosted: Thu Jun 15, 2006 2:03 pm    Post subject: Re: ANNOUNCE: comp.soft-sys.octave has been created Reply with quote

Martin Eisenberg wrote:
Quote:
Himanshu Chauhan wrote:


This group hasn't been added by google yet. I am, atleast,
waiting for them to do so.


What do you mean?
http://groups.google.com/group/sci.math.num-analysis

smna, yes, but not the new Octave group Smile
Back to top
Himanshu Chauhan
science forum beginner


Joined: 15 Jun 2006
Posts: 2

PostPosted: Thu Jun 15, 2006 3:47 pm    Post subject: Re: ANNOUNCE: comp.soft-sys.octave has been created Reply with quote

Martin Eisenberg wrote:
Quote:
Himanshu Chauhan wrote:

This group hasn't been added by google yet. I am, atleast,
waiting for them to do so.

What do you mean?
http://groups.google.com/group/sci.math.num-analysis


Martin


Oh My fault in posting. Actually I meant "comp.soft-sys.octave" hasn't
been added by google yet.

Himanshu

--
----------------------------------------
Himanshu Chauhan
MCA (Final Year)
I.G. National Open University
Jaipur (India)

Mobile:(+91)-(98292)-(92757)
Web: http://members.lycos.co.uk/hschauhan
Email: hs.chauhan@gmail.com

"Education is what remains after one
has forgotten everything he learned
in school." -- A. Einstein.
----------------------------------------
Back to top
Google

Back to top
Display posts from previous:   
Post new topic   Reply to topic Page 18 of 19 [276 Posts] Goto page:  Previous  1, 2, 3, ..., 16, 17, 18, 19 Next
View previous topic :: View next topic
The time now is Thu Dec 14, 2017 5:01 pm | All times are GMT
Forum index » Science and Technology » Math » num-analysis
Jump to:  

Similar Topics
Topic Author Forum Replies Last Post
No new posts how to deduce a number validation algorithm? Tim_Mac Math 1 Fri Jul 21, 2006 10:43 am
No new posts uni. convergence bill1158 Math 3 Wed Jul 19, 2006 10:59 am
No new posts convergence of probability measures pkg Math 0 Sat Jul 15, 2006 7:15 pm
No new posts analysis with uniform convergence.. mina_world Math 4 Fri Jul 14, 2006 8:26 am
No new posts Name of algorithm for pairwise comparison ? Paul Nutteing Math 10 Fri Jul 14, 2006 6:55 am

Copyright © 2004-2005 DeniX Solutions SRL
Other DeniX Solutions sites: Electronics forum |  Medicine forum |  Unix/Linux blog |  Unix/Linux documentation |  Unix/Linux forums  |  send newsletters
 


Powered by phpBB © 2001, 2005 phpBB Group
[ Time: 0.0316s ][ Queries: 16 (0.0063s) ][ GZIP on - Debug on ]