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Marius - It depends on the precise problem you're trying to solve, i.e. do you want just _any_ ellipsoid that encloses all the atoms, or do you actually want the smallest ellipsoid (i.e. minimal volume). If the former then the suggested method is sufficient, but note that there's no reason why the smallest ellipsoid should have the same centre or principal axes as the inertial ellipsoid. If you want the precise minimal ellipsoid then it's a minimisation problem. I've done it for the case of the smallest sphere enclosing a set of points, for the ellipsoid case it would be a matter of adding 5 more variables (i.e. 9 altogether) to the minimisation. Note that in the sphere case as for the ellipsoid there's no reason why the minimal sphere should be centred at the centroid of the points (think about the case of a cluster of points plus 1 outlier). -- Ian > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Tim Gruene > Sent: 08 December 2005 16:10 > To: Marius Schmidt > Cc: [EMAIL PROTECTED] > Subject: [ccp4bb]: Re: your mail > > *** For details on how to be removed from this list visit the *** > *** CCP4 home page http://www.ccp4.ac.uk *** > > > Hi, > > unless you need the ellipsoid oriented, you could use > moleman2 to align the axes of inertia and then type 'stats' > to see the extend of the molecule. > > Is this what you are looking for? > > Tim > -- > Tim Gruene > Institut fuer anorganische Chemie > Tammannstr. 4 > D-37077 Goettingen > > GPG Key ID = A46BEE1A > > > On Thu, 8 Dec 2005, Marius Schmidt wrote: > > > *** For details on how to be removed from this list visit the *** > > *** CCP4 home page http://www.ccp4.ac.uk *** > > > > > > Dear ccpbb'er, > > is there anyone out there who has a chunk of code that can > determine > > an ellipsoid from a set of coordinates. > > In this partiular example, a chromophore has to be > inscribed into an > > ellipsoid and the length of the 3 axes of the ellipsoid has to be > > determined. Well, I could try to write the code myself, but maybe > > someone encountered that problem before and can help me out. > > > > Looking forward to many responses > > > > M. Schmidt > > > > > > > > PD Dr. habil. Marius Schmidt > > Physikdepartment E17 > > Technische Universitaet Muenchen > > James Franck Strasse > > 85747 Garching/Germany > > email: [EMAIL PROTECTED] > > phone: +49-(0)89-2891-2550 > > fax: +49-(0)89-2891-2548 > > > > Disclaimer This communication is confidential and may contain privileged information intended solely for the named addressee(s). It may not be used or disclosed except for the purpose for which it has been sent. If you are not the intended recipient you must not review, use, disclose, copy, distribute or take any action in reliance upon it. If you have received this communication in error, please notify Astex Therapeutics Ltd by emailing [EMAIL PROTECTED] and destroy all copies of the message and any attached documents. Astex Therapeutics Ltd monitors, controls and protects all its messaging traffic in compliance with its corporate email policy. The Company accepts no liability or responsibility for any onward transmission or use of emails and attachments having left the Astex Therapeutics domain. Unless expressly stated, opinions in this message are those of the individual sender and not of Astex Therapeutics Ltd. The recipient should check this email and any attachments for the presence of computer viruses. Astex Therapeutics Ltd accepts no liability for damage caused by any virus transmitted by this email. E-mail is susceptible to data corruption, interception, unauthorized amendment, and tampering, Astex Therapeutics Ltd only send and receive e-mails on the basis that the Company is not liable for any such alteration or any consequences thereof.
