Path: utzoo!utgpu!jarvis.csri.toronto.edu!neat.cs.toronto.edu!krj Newsgroups: ut.na From: krj@na.toronto.edu (Ken Jackson) Subject: NAgMAg v89 #24 Message-ID: <89Nov24.103331est.2414@neat.cs.toronto.edu> Organization: Department of Computer Science, University of Toronto Distribution: ut Date: 24 Nov 89 15:35:11 GMT NAgMAg Friday, November 24 1989 Volume 89 Issue 24 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% The official electronic digest of the NAG Users Association %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Today's Topics On-line Information Supplement New library routines New library routines? %% %% Well some response from my request for what new routines people %% would like to see in the library. There must be lots of users %% out there who come along to their computing centres etc. saying %% why isn't there a routine to do x. So let's have a few more %% suggestions. %% %% Tim %% --------------------------- Date: Wed, 15 Nov 89 16:57:34 PST From: Jerry Berkman Subject: On-line Information Supplement I recently installed the generic UNIX version of the NAG online information supplement for the Mark 13 library on our Cray X-MP running UNICOS 4.0. I think this is a fine service. Here are some comments and recommendations. 1. News I found a topic called "news" which is titled: "NAG FORTRAN LIBRARY MARK13 NEWS" It contains everything in sections 2-5 of the "Fortran Mark 13 News" at the beginning of Volume 1 of the printed NAG Fortran Library Manual: New Routines, Withdrawn Routines, Routines Scheduled for Withdrawal, Superseded Routines, Routines Revised at Mark 13 NAG should also include section 1, "New Features of Mark 13" so the online news is complete (I added it manually). NAG should also document this section by mentioning it exists in the printed documentation and by adding it to the subject index, subject.d . I found it purely by accident. 2. A00AAF This routine should be described, rather than aliasing a reference to the topic "local". 3. INDEX The generic UNIX version uses "index" as an intrinsic in one program unit of help.f and uses "index" as the name of the block data generated by index.f . This is legal Fortran 77 (see ANSI standard section 18.1.2), but doesn't work with Cray compilers. Cray acknowledges this is a bug which will be fixed in the future. But for now you must change format 97 of index.f. By the way, IBM's VS FORTRAN also can not handle this condition and IBM has stated they will NOT fix this (Problem 4X650) so future AIX sites will probably stumble on this. And there may be other compilers which stumble on this. 4. /IO/ The generic UNIX version unnecessarily mixes chararacter and non-char. variables in common block IO in help.f . This is non-standard and there are compilers which enforce the standard which will not compile help.f . On our Cray system, CFT won't compile this, CFT77 does. However, CFT77 3.0 with optimization on (by default) generates bad code for assign in help.f . This has been fixed in CFT77 3.1 which we now use. - Jerry Berkman, U.C. Berkeley, USA jerry@violet.berkeley.edu (internet) jerry at ucbviole (bitnet) (415)642-4804 (phone) --------------------------- Date: Fri, 17 Nov 89 16:36:02 GMT From: "Mr.C.Daly" Subject: New library routines Tim, you ask for suggestions for new Nag routines, so here goes - but I have only recently started to receive Nagmag, so my apologies if this topic has already been raised. G05CAF has a period of 10**17 and has been very satisfactory. However there is an increasing need for pseudo-random number generators with longer periods as machines become more and more powerful, and there is also a need for the ability to initiate simultaneously a large number of independent series of pseudo-random numbers - when running a job on a multi-transputer system, for example. Both of these needs would appear to be met by a generator called RANMAR, due to Marsaglia and Zaman, details of which will be found in CERN report DD/88/22 whose author is F.James. This requires two integer seeds, each in the approximate range 0 to 30000. It would appear that these allow the possibility of 900 million independent series, each of length about 10**30. It is completely portable, giving bit-identical results on all machines with at least 24-bit mantissas in the floating point representation ( ie all the common computers of 32 bits or more). If this generator is as good as it sounds then I suggest that we ought to find a place for it in the Nag repertoire. Charles Daly --------------------------- Date: Sun,19 Nov 89 16:15:03 GMT From: David_Rhead@vme.ccc.nottingham.ac.uk Subject: New library routines? In NagMag #23, Tim asks for suggestions for new facilities in the main Fortran Library. I'd like to see routines in the E04 chapter for minimizing a sum of squares of non-linear functions subject to simple bounds on the variables. i.e., routines that bear the same relation to the E04Fs, E04Gs and E04Hs that the E04Js, E04Ks and E04Ls bear to the E04Cs, E04Ds and E04Es. Such routines would be of great value to people who are fitting models to data (and my guess is that there are more such people than there are people who have objective functions that are not sums-of-squares). It is very common for people who are fitting models to data to know that the fitted values must be in a certain range: either for modelling reasons (e.g., an exponential must be a decaying one) or for programming reasons (e.g., if this goes negative, I won't be able to evaluate that). At the moment, if a user has a sum-of-squares problem with bounds, one has to advise them to use a general routine (bad, because the routine cannot take advantage of the sum-of-squares structure and, as far I remember, will be solving a worse-conditioned problem than the original one) or ignore the bounds and hope (bad, because it may be a matter of experimenting with different starting points until the algorithm finds a path from starting point to minimum that happens not to violate any bounds en route). In any case, surely the rationalle that applies in the general case also applies in the sum-of-squares case. It is very rare that absolutely any values in the range (-infinity,+infinity) will really be acceptable, if only because, at some point, we would say that the problem is badly scaled. It would make more sense to have "just bounded routines" rather than "just unbounded routines" in the sum-of-squares case, in the same way that, in the general case, NAG seems to be withdrawing the "unbounded black-boxes" in favour of "bounded black-boxes". David Rhead --------------------------- %% For NAGUA membership details contact: %% Janet Bentley, Administrator NAGUA, %% Shore Lane Farm, Blackstone Edge Old Road, %% LITTLEBOROUGH, Lancashire, OL15 0LQ, UK. %% %% For other NAGUA enquiries contact: %% Caroline J Foers %% NAGUA Coordinator, %% NAG Users Association, %% PO Box 426, %% Oxford, OX2 8SD, U.K. %% %% e-mail caroline@uk.co.nag.vax %% %% Replies or submissions to nagmag@uk.ac.ukc %% Distribution changes to nagmag-request@uk.ac.ukc %% %% END OF ISSUE --------------------- Reposted by Prof. Kenneth R. Jackson, krj@na.toronto.edu (on Internet, CSNet, Computer Science Dept., ARPAnet, BITNET) University of Toronto, krj@na.utoronto.ca (on CDNnet and other Toronto, Ontario, X.400 nets (Europe)) Canada M5S 1A4 ...!{uunet,pyramid,watmath,ubc-cs}!utai!krj (Phone: 416-978-7075) (on UUCP) (FAX: 416-978-4765) Brought to you by Super Global Mega Corp .com