From: Beliavsky on 5 Mar 2010 10:10 Is there a public domain Fortran code to compute the expectation value of the Mth largest out of N standard normal variates? I can simulate this, of course, but maybe there are fast but accurate approximations.
From: Lurker on 5 Mar 2010 10:28 You might find someting here... http://jblevins.org/mirror/amiller/ "Beliavsky" <beliavsky(a)aol.com> wrote in message news:6c4a11a7-dff5-4529-8225-6adc5b18a4bd(a)q15g2000yqj.googlegroups.com... > Is there a public domain Fortran code to compute the expectation value > of the Mth largest out of N standard normal variates? I can simulate > this, of course, but maybe there are fast but accurate approximations.
From: Gordon Sande on 5 Mar 2010 10:56 On 2010-03-05 11:10:19 -0400, Beliavsky <beliavsky(a)aol.com> said: > Is there a public domain Fortran code to compute the expectation value > of the Mth largest out of N standard normal variates? I can simulate > this, of course, but maybe there are fast but accurate approximations. Google yielded Algorithm AS 177: Expected Normal Order Statistics (Exact and Approximate) J. P. Royston Journal of the Royal Statistical Society. Series C (Applied Statistics), Vol. 31, No. 2 (1982), pp. 161-165 (article consists of 5 pages) when asked for "normal order statistics". I have often been told that order statistics are an example of a computation requiring very high precision due to extreme cancelation so one should use one of the symbolic manipualtion packages and be patient. It is the sort of thing that may have approxiamtion formulae of varying accurracy. The title of this algorithm reinforces these notions.
From: Beliavsky on 5 Mar 2010 11:45 On Mar 5, 10:28 am, "Lurker" <spamk...(a)spamkill.co.uk> wrote: > You might find someting here... > > http://jblevins.org/mirror/amiller/ Thanks to you and to Gordon Sande. The relevant code is at http://jblevins.org/mirror/amiller/as177.f90 .
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