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Voronoi indexes (was philisophical /UnRebolish /Interleave)

 [1/2] from: webdev::accglobal::net at: 27-Sep-2000 0:21


This is a multi-part message in MIME format. ------=_NextPart_000_0023_01C02818.D7663620 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable This is Not Rebol specific. Spatial indexing using voronoi tesselations. Sensing an interest by some of the list members in this subject matter as well as its' possible trancendence into a Rebol application... If you are interested in the practical and theoretical aspects of spatial indexing and related geometry then go visit: http://voronoi.com/ The subject matter applies to many disciplines that have a significant spatial aspect such as chemistry, medicine, imaging, and geography to name but a few. It makes for a much more stimulating intellectual fare than Bill Gates latest bid for world domination or why Rebol has not been ported to my lavatory appliances. Enjoy... ----- Original Message ----- From: <[joel--neely--fedex--com]> To: <[list--rebol--com]> Sent: Tuesday, September 26, 2000 9:15 AM Subject: [REBOL] Re: Philosophical (was "UnRebolish") commentary
> > [webdev--accglobal--net] wrote: > > ... Do not
<<quoted lines omitted: 93>>
> to think of Edsger! > -jn-
------=_NextPart_000_0023_01C02818.D7663620 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=windows-1252" http-equiv=Content-Type> <META content="MSHTML 5.00.2314.1000" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial size=2>This is Not Rebol specific.<BR>Spatial indexing using voronoi tesselations.<BR>Sensing an interest by some of the list members in this subject matter as<BR>well as its' possible trancendence into a Rebol application...<BR><BR>If you are interested in the practical and theoretical aspects of spatial<BR>indexing and related geometry then go visit: <A href="http://voronoi.com/">http://voronoi.com/</A><BR>The subject matter applies to many disciplines that have a significant<BR>spatial aspect such as chemistry, medicine, imaging, and geography to name<BR>but a few. It makes for a much more stimulating intellectual fare than Bill<BR>Gates latest bid for world domination or why Rebol has not been ported to my<BR>lavatory appliances.<BR><BR>Enjoy...<BR><BR>----- Original Message -----<BR>From: <<A href="mailto:[joel--neely--fedex--com]">[joel--neely--fedex--com]</A>><BR>To: <<A href="mailto:[list--rebol--com]">[list--rebol--com]</A>><BR>Sent: Tuesday, September 26, 2000 9:15 AM<BR>Subject: [REBOL] Re: Philosophical (was UnRebolish ) commentary<BR><BR><BR>> > <A href="mailto:[webdev--accglobal--net]">[webdev--accglobal--net]</A> wrote:<BR>> > ... Do not<BR>> > attempt to do anything more serious than a napkin sketch of this<BR>> > method without the supervision of an adult or perhaps an attending<BR>> > physician unless you wish to go numerically mad with something akin to<BR>> > a division by zero.<BR>>
><BR>><BR>>
ROTFL!<BR>><BR>> ><BR>> > Thanks for the feedback, ...<BR>>
><BR>><BR>> Thanks for the question!<BR>><BR>> ><BR>> >
it was most enlightening and informative.<BR>> ><BR>><BR>> .. and fun!&nbsp; AFAIAC, it provided a welcome break from a very<BR>> frustrating network infrastructure problem.&nbsp; Also, by concidence,<BR>> it arrived the same day I found the following link:<BR>><BR>>&nbsp;&nbsp;&nbsp;&nbsp; <A href="http://www.cs.utexas.edu/users/EWD/">http://www.cs.utexas.edu/users/EWD/</A><BR>><BR>> to a page bearing the title<BR>><BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; In Pursuit of Simplicity<BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; the manuscripts of<BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Edsger W. Dijkstra<BR>><BR>> [If you don't want to bother with reading the remainder of this<BR>>&nbsp; note, please feel free to skip it.&nbsp; But PLEASE don't skip the<BR>>&nbsp; opportunity to look through the collection of papers under the<BR>>&nbsp; above page!]<BR>><BR>><BR>> For those who've had the pleasure of reading his EWD series, this<BR>> site is a MAJOR treat.&nbsp; Dijkstra is a world-class thinker and<BR>> writer in computing science whose entire career is been marked<BR>> by the pursuit of simplicity and elegance in the description and<BR>> design of algorithms and proofs.<BR>><BR>> Although his writings are off the beaten track, and though he<BR>> uses his own notation for some things, and though he can be very<BR>> intellectually demanding (all of which remind me of REBOL),<BR>> almost everything he has written has hidden rewards to the reader<BR>> who is patient enough to work through it.<BR>><BR>><BR>> His contributions to programming include such crown jewels as:<BR>><BR>> * invention of the semaphore , now widely used as a means of<BR>>&nbsp;&nbsp; synchronizing concurrent threads/processes,<BR>><BR>> * the eponymous algorithm for finding the shortest path<BR>>&nbsp;&nbsp; between two points in a graph,<BR>><BR>> * the first clear description of using a stack to support<BR>>&nbsp;&nbsp; procedure scoping/entry/exit (created during early<BR>>&nbsp;&nbsp; implementation efforts for Algol 60!),<BR>><BR>> * a lovely, minimalist, nondeterministic programming notation<BR>>&nbsp;&nbsp; used for the design and proof of programs (a small part of<BR>>&nbsp;&nbsp; which I implemented in REBOL a few months back with great<BR>>&nbsp;&nbsp; assistance from the members of this list -- the EWD/if and<BR>>&nbsp;&nbsp; EWD/do selection and iteration structures).<BR>><BR>> He is probably best known to the larger programming community<BR>> as the author of the letter published under the title,<BR>> go to Considered Harmful in the Communications of the ACM,<BR>> which (for good or ill) is usually credited as the spark that<BR>> ignited the structured programming movement (although he should<BR>> not be blamed for all of the things that have been done under the<BR>> cover of that banner!)<BR>><BR>><BR>> His career-long pursuit of beauty as a prime criterion of quality<BR>> in programming strikes me as wholly aligned with what I perceive<BR>> as "the spirit of REBOL" (and I'm not saying that just to<BR>> achieve ob-REBOL-relevance ;-)&nbsp; In particular, let me recommend<BR>> that you give a close (and patient! ;-) reading to<BR>><BR>>&nbsp;&nbsp;&nbsp;&nbsp; <A href="http://www.cs.utexas.edu/users/EWD/MCReps/MR34.PDF">http://www.cs.utexas.edu/users/EWD/MCReps/MR34.PDF</A><BR>><BR>> which -- although written in 1961 (!) -- states forcefully that<BR>> it is the responsibility of a programming language to assist<BR>> the programmer in clearly stating reliable algorithms, and that<BR>> this responsibility is more fundamental than simply minimizing<BR>> CPU cycles or memory bytes.&nbsp; [Over-simplified araphrase, and any<BR>> errors therein, are my fault.]<BR>><BR>> Dijkstra's forceful, uncomprimising, artistic personality and<BR>> attitude appear almost quixotic (in the fullest sense! ;-),<BR>> especially when he tackles none-too-subtly the behavior of<BR>> IBM (the Microsoft of the 60s and 70s).&nbsp; His article entitled,<BR>> "How do we tell truths that might hurt?", available at<BR>><BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <A href="http://www.cs.utexas.edu/users/EWD/ewd04xx/EWD498.PDF">http://www.cs.utexas.edu/users/EWD/ewd04xx/EWD498.PDF</A><BR>><BR>> (from 1975) is a collection of pointed sayings including:<BR>><BR>>&nbsp;&nbsp;&nbsp;&nbsp; "The problems of business administration in general<BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; and data base management in particular are much too<BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; difficult for people that think in IBMerese, com-<BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; pounded with sloppy English."<BR>><BR>>&nbsp;&nbsp;&nbsp;&nbsp; "Many companies that have made themselves dependent<BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; on IBM-equipment (and in doing so have sold their<BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; soul to the devil) will collapse under the sheer<BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; weight of the unmastered complexity of their data<BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; processing systems."<BR>><BR>> and (the last quotation -- I promise!) one that deserves to<BR>> be tatooed on the forehead of every programmer (and inside<BR>> the eyelids of every programming language designer!)<BR>><BR>>&nbsp;&nbsp;&nbsp;&nbsp; The tools we use have a profound (and devious!)<BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; influence on our thinking habits, and, therefore,<BR>>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; on our thinking abilities. <BR>><BR>> The experience of over 25 years' of exposure to Dijkstra's ideas<BR>> is one of the most fundamental reasons why I appreciate REBOL as<BR>> much as I do -- and probably also why I sometimes come off as<BR>> such a curmudgeon!&nbsp; I'd be flattered if either caused someone<BR>> to think of Edsger!<BR>><BR>> -jn-<BR>><BR>><BR></FONT></DIV></BODY></HTML> ------=_NextPart_000_0023_01C02818.D7663620--

 [2/2] from: joel:neely:fedex at: 27-Sep-2000 8:09


> [webdev--accglobal--net] wrote: > This is Not Rebol specific.
<<quoted lines omitted: 5>>
> of spatial indexing and related geometry then go visit: > http://voronoi.com/
Thanks! I've forwarded the reference on to a collegue of mine who is interested in that very thing! -jn-

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