Hi Bernhard Oh dear we're getting into naming issues again!! I'm not clear what's the distinction you're making between 'A Rice function' and 'THE Rice function' since my understanding was that there was only one form of Rice distribution, i.e. the one defined here: http://en.wikipedia.org/wiki/Rice_distribution .
As for the 'Sim function', one problem seems to be that crystallographers appear to have used this to mean two different things: 1) the PDF of the *(complex) structure factor*, which is really just a 2-D Gaussian, and 2) the PDF of the *(real) structure amplitude*, which is the Rice distribution, and which is the result of integrating out of the phase (which gives the I0 component of the Rice distribution) from the structure factor distribution. I don't have Sim's original paper to hand so I don't know know how he defined it, or even whether he ever called his function a 'Rice function'. However it would seem more logical to call the integrated (Rice) form of Sim's function 'the Sim distribution' and not use this term to mean the 2-D Gaussian. As for ACNSFD & CCNSFD, I'm not clear what you mean, could you be more specific, in particular do you mean the *structure amplitude* distributions? Cheers -- Ian > -----Original Message----- > From: owner-ccp...@jiscmail.ac.uk [mailto:owner-ccp...@jiscmail.ac.uk] On > Behalf Of Bernhard Rupp > Sent: 09 April 2009 07:06 > To: CCP4BB@jiscmail.ac.uk > Subject: Rice vs Sim vs ACNSFD > > Dear All, > > > > I am unsure about the likelihood function nomenclature. > > > > I have seen the Sim function called the Rice function, and > > aIso have read the acentric conditional normalized structure factor > distribution (ACNSFD) > > called the Rice function (the centric conditional normalized structure > factor distribution > > consistently seems to be the Woolfson distribution). > > > > Looking at both the Sim and ACNSFD, they look like the > > pdf in figure 6 of Rice ( who interestingly, attributes the function > > to a Mr Bennett in 'some unpublished work'. So I guess Rice made the > Race). > > > > So believe that > > a) both the Sim distribution and the ACNSFD > > are A Rice function, not THE Rice function. Agreeable? > > > > b) is there a proper name for the ACNSFD or generally > > for the acentric conditional structure factor distribution? > > > > Thx, BR > > ----------------------------------------------------------------- > Bernhard Rupp > 001 (925) 209-7429 > +43 (676) 571-0536 > b...@qedlife.com > b...@ruppweb.org > http://www.ruppweb.org/ > ----------------------------------------------------------------- > > Die Wissenschaft und die Wissenschafter werden > > von Angst regiert - Angst vor der öffentlichen > > Meinung, Angst vor religiöser Intoleranz, vor > > politischem Druck und vor allem Angst vor > > Heuchelei und Vorurteilen. > > > > William Masters und Virginia Johnson, 1970 > ----------------------------------------------------------------- > > > > 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 i.tic...@astex-therapeutics.com 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. Astex Therapeutics Ltd., Registered in England at 436 Cambridge Science Park, Cambridge CB4 0QA under number 3751674
