From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=BAYES_00,FORGED_HOTMAIL_RCVD2, FREEMAIL_FROM autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: 103376,d04d2547435a643e X-Google-NewGroupId: yes X-Google-Attributes: gida07f3367d7,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Received: by 10.68.238.65 with SMTP id vi1mr12915731pbc.7.1339950838631; Sun, 17 Jun 2012 09:33:58 -0700 (PDT) Path: l9ni61660pbj.0!nntp.google.com!news1.google.com!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail From: Austin Obyrne Newsgroups: comp.lang.ada Subject: Re: True or False ? Date: Sun, 17 Jun 2012 09:33:58 -0700 (PDT) Organization: http://groups.google.com Message-ID: References: <17029032-5398-4754-8a85-116d595ce59c@googlegroups.com> <87haual1o2.fsf@ludovic-brenta.org> <67e507a5-940f-4168-becb-0fd614709bea@googlegroups.com> NNTP-Posting-Host: 109.148.165.193 Mime-Version: 1.0 X-Trace: posting.google.com 1339950838 6863 127.0.0.1 (17 Jun 2012 16:33:58 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Sun, 17 Jun 2012 16:33:58 +0000 (UTC) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=109.148.165.193; posting-account=pmkN8QoAAAAtIhXRUfydb0SCISnwaeyg User-Agent: G2/1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Date: 2012-06-17T09:33:58-07:00 List-Id: On Sunday, June 17, 2012 3:14:48 PM UTC+1, Martin Trenkmann wrote: > On 06/17/2012 12:35 PM, adacrypt wrote: > > On Sunday, June 17, 2012 10:37:17 AM UTC+1, Ludovic Brenta wrote: > >> Austin writes on comp.lang.ada: > >>> Do you know if these sort programs are used in real world programming > >>> today ? > >> > >> In our two-million-line mission-critical software we use heap sort and > >> tree sort but not quick sort. > >> > >> -- > >> Ludovic Brenta. > > > > Many thanks. > > > > I have never heard of heap save - is this to be found in academic books= ? > > I'm taking it then that there has not been any huge advance in sorting = methods over the past twenty years. > > > > Could I pick your brains a bit further. > > > > My scheme is ideal for accessing vast programs of millions of lines of = source code like you mentioned - I tag every variable as it is being keyed = in at the outset (at creation time) and then disable it until it is needed = (I comment it out ) and if I do need it I simply uncomment it for sorting b= y a specially developed sorting method. The tags can be stored up front or= even stored in a file in memory for systematic calling by the main program > > > > Perhaps you would have a look at this new method later when I go public= . > > > > Question - would it call it a big asset to improve on sorting methods? = - given that there is so much computer power available to day - poor or eve= n bad methods are getting by without notice? > > > > Many thanks for your help again. > > > > Regards - Austin. > > >=20 > Have you done an extensive research of sorting algorithms [1] before=20 > inventing your scheme or any comparison regarding best/avg/worst case=20 > runtime complexity? >=20 > I think there is still much research in this area going on and depending= =20 > on the real use case many hybrid algorithms exist. For example the C++=20 > std::sort from GCC uses intosort [2] which is a hybrid of quicksort and= =20 > heapsort. Python and Java 7, as far as I know, use timsort [3], a hybrid= =20 > of merge sort and insertion sort. >=20 > So I would be careful stating that "classroom" algorithms are not used=20 > in industry. >=20 > Anyway, the description of your scheme is not clear to me, but it=20 > reminds me a bit of counting sort [4], just to be sure not to reinvent=20 > the wheel. >=20 > Regards -- Martin Trenkmann >=20 > [1] http://en.wikipedia.org/wiki/Sorting_algorithm > [2] http://en.wikipedia.org/wiki/Introsort > [3] http://en.wikipedia.org/wiki/Timsort > [4] http://en.wikipedia.org/wiki/Counting_sort No, I have not done any research on current sort algorithms. The replies from you and the other readers have brought me up to date howev= er. I can see now that there is still some research going on and that is what I= really wanted to know - it is not a closed book by any means. My scheme will make all of these other sort programs redundant possibly but= I am not clear why in my own mind - is speed still the essence in sort pro= grams? I think you will like the connection with Ada when it comes. I will of course watch out now for making staements about academia. Could I ask you to watch this space so to speak when I go public with my sc= heme - there is alot of Ada in it and it may even become a bench mark for c= omparisons with the existing sort algorithms. Many thanks for your advice - Austin=20