Back from vacation and 4 new articles online ! :-) - Printable Version +- HP Forums (https://archived.hpcalc.org/museumforum) +-- Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum-1.html) +--- Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum-2.html) +--- Thread: Back from vacation and 4 new articles online ! :-) (/thread-122068.html) |
Back from vacation and 4 new articles online ! :-) - Valentin Albillo - 08-20-2007 Hi all:
Speaking of vacations, among many other things I've taken advantage of the free time and quiet environment I've enjoyed to write *three* new articles, all of them focused in the new HP35s (which I carried with me as my sole computing device in order to familiarize myself with its pros and cons), which will be promptly submitted to Datafile for their eventual publication in the very next issue, so you'll be able Meanwhile, thanks to the invaluable help of my 15-year old daughter Laura (who got a Nintendo DS plus assorted game cards for her considerable efforts), my humble HP calculator site boasts a brand-new aspect and layout, and to commemorate the occasion I've just uploaded there and made freely available for download the following four articles of mine which were previously featured in Datafile, all of them in PDF format:
Long Live the HP-35 !
This 5-page article, belonging to my ongoing "Long Live ..." series, is intended as a commemorative article for the HP-35's 35th anniversary, and I think you'll agree it's quite an original approach to it. It does include three sample applications featuring four small programs, addressing such topics as root finding and numerical integration, as well as providing the appropriate historical context Boldly Going - Matrix Square Root
To provide a taste for the series, this first article deals with this task of finding the matrix square root of square matrices. Two full programs are featured: a 7-line subprogram for the HP-71B which can deal with real- or complex-valued NxN matrices, and a 45-step routine for the HP-15C which will find the square root of real-valued matrices up to 4x4. Full examples are provided, with comments and notes, as well as the underlying algorithm. Boldly Going - Identifying Constants
It's a relatively simple program which provides basic functionality for an advanced, very useful and most impressive feature which is nevertheless absent in our beloved machines’ built-in instruction sets, namely identifying numeric constants, i.e., the capability of, given some real, numeric value, to try and identify its exact symbolic form if possible, and that failing, to provide an approximate symbolic expression of user-specified relative accuracy.
This will allow us to perform some pretty nifty feats, such as give exact, symbolic
The full 14-page article boasts more than 40 worked out examples, as well as three detailed extensions, the last being an 'exercise' for the reader, solution included ! :-)
This first article deals with the topic of prime counting, i.e., finding out how many prime numbers there are up to a given limit N. For large N, generating all primes up to N and returning the count is prohibitively expensive in terms of running time and/or memory usage. What can we do about it when N goes sky-high (say 1010, 1015, or more) ? The article features an 8-line user-defined function for the HP-71B to accomplish the feat very quickly, as well as several comparative examples against other well-known prime counting procedures.
That's all for now, you can download them for free at my site, and I sincerely hope you'll enjoy them and will consider them good read for these quiet summer evenings (26 pages in all, nearly a full regular Datafile issue !). Any and all comments are really welcome, thanks in advance for them and
Best regards from V.
Edited for typos Edited: 20 Aug 2007, 7:03 a.m.
Re: Back from vacation and 4 new articles online ! :-) - hugh steers - 08-20-2007 excellent! i like the site improvements, especially the calculator image branding.
Quote:unless you have satellite broadband that is.
cheers!
Re: Back from vacation and 4 new articles online ! :-) - Vincze - 08-20-2007 My friend, it appears you page must be broken. The main image in the center is 404 and it redirects to Lycos, and the items on the side, look like broken images.
Re: Back from vacation and 4 new articles online ! :-) - Valentin Albillo - 08-20-2007 Thanks for the warning, Vincze, but it works Ok to me.
¿ Perhaps some configuration problem in your browser and/or
The free, french Lycos server I'm using to host my pages
Anyway, should you still be unable to reach some of the
Best regards from V.
Re: Back from vacation and 4 new articles online ! :-) - Valentin Albillo - 08-20-2007 Hi, Hugh ! Hugh posted:
"excellent! i like the site improvements, especially the calculator image branding. " I'll pass you comments on to Laura, she'll be *very* happy ! She's a fledgling "web designer" and is very eager to get feedback for her very first "professional" work, so thank you very much for providing it.
Also, I hope you'll enjoy the 26-pages worth of articles :-)
Re: Back from vacation and 4 new articles online ! :-) - Vincze - 08-20-2007 I disable everything and nothing. Only thing I see on page is your counter, and the menu on left. I try and click on link for each menu item, but it just shows "Page non trouvée" and then go to main Lycos page. Very strange.
Re: Back from vacation and 4 new articles online ! :-) - Valentin Albillo - 08-20-2007
Strange indeed ... I've tried just now (IE 6.0) and this
Re: Back from vacation and 4 new articles online ! :-) - Alain Mellan - 08-20-2007 I get the same "Page non trouvée".
Re: Back from vacation and 4 new articles online ! :-) - Valentin Albillo - 08-20-2007 Thanks a lot, I'll have Laura look into it ASAP. Best regards from V.
Re: Back from vacation and 4 new articles online ! :-) - Ed Look - 08-20-2007 Gentlemen, it appears to work in Internet Explorer, but not Mozilla Firefox.
Re: Back from vacation and 4 new articles online ! :-) - Vincze - 08-20-2007 Ah, I think I see problem. I go into IE and try, and it work. I normally use for 99.999999% of all things Firefox browser, and it not work in there. I wonder why that they case. ActiveX?
Re: Back from vacation and 4 new articles online ! :-) - Alain Mellan - 08-20-2007 Nothing that complicated. I think when Explorer sees a \ (backslash) in a URL, it automatically translates to a / (forward slash) when sending a request to the web server. Firefox does not.
-- alain.
Re: Back from vacation and 4 new articles online ! :-) - bill platt - 08-20-2007 Aha!
That's it! (I couldn't get it to work either). The IE Windoze thing again :-(
Re: Back from vacation and 4 new articles online ! :-) - Vincze - 08-20-2007 I just add IE render to Firefox, and then turn on flux capacitor, and all is fine in Firefox. Anything to upset Mr Gates.
Re: Back from vacation and 4 new articles online ! :-) - Dave Shaffer (Arizona) - 08-20-2007 Valentin's page also shows up fine with Netscape 8.1 (I'm a real dinosaur when it comes to browsers, and I, too, will do almost anything to not use Micro$oft products!)
In fact, those of you who have never tried WordPerfect instead of Word should give it a try!
Re: Back from vacation and 4 new articles online ! :-) - Ed Look - 08-20-2007 Anybody remember AmiPro (by Lotus) in the days of Windows 3.1? I was cleaning out some old manuals and the like and I found literature for AmiPro. I liked it much better than Word or WordPerfect then... and I think that's a bit of high praise from me as I preferred the DOS command line WordStar, maybe WordPerfect, over any GUI based word processor. Yeah, I found the old WordStar manuals, too. I even found some literature on using VMS (ugh!... what horrible memories... ) on some old mainframe.
But none of this is older than my HP-34C with its Cylonic red LED eyes, and its spiral bound manual that could double as a high school or college math text. Yeah, it's also got that laminated quick reference card!
FIXED ! It should work now. Please try and tell me. [NT] - Valentin Albillo - 08-20-2007 Sorry for the inconvenience, thanks for bringing the problem to my attention, and
Best regards from V.
Re: Back from vacation and 4 new articles online ! :-) - Vincze - 08-20-2007 I remember AmiPro. I hate to say this, but I really did not like it.
I have OpenOffice at home, and it very nice and free. I also have M$ Office too, but I wanted to see what OpenOffice like and it very nice. I can use documents from both system back and forth just fine. Again, to upset Mr Gates.
Yes, it work now - Vincze - 08-20-2007 Yes, it work now, what did you have to do?
Re: Back from vacation and 4 new articles online ! :-) - James M. Prange (Michigan) - 08-21-2007 With Firefox 2.0.0.6, the page looked just fine the first time that I loaded it. However, if I use Tools > Options... > Content, and uncheck "Load images automatically", of course I get the "broken images". I suspect that any problems with viewing this page with Firefox is a matter of browser configuration. Something else to check would be the configuration of extensions, such as AdBlock.
Regards, Re: Yes, it work now - Valentin Albillo - 08-21-2007
Simply changing all incorrect "\" to the correct "/", as
Best regards from V.
Re: Yes, it work now - Giancarlo (Italy) - 08-21-2007 Hi Valentin, welcome back :-) Re: Yes, it work now - Valentin Albillo - 08-21-2007 Hi, Giancarlo: Giancarlo wrote:
That's a way for she to gain experience and training to deal with real professional demands well in advance. And after all the hard work, lots of googling for site creation tutorials, desperation when something didn't work as it should, excitement when finally the bulb did light up, and satisfaction with the final product being duly accepted by the "demanding customer" (i.e., me), she's more than happy with herself and convinced she can overcome non-trivial difficulties, learn a lot in the process, and enjoy her new Nintendo DS plus game cards of her choice. The bottom line is both her knowledge and her self-esteem have increased immensely with this "real world" little stratagem of mine. And she's asking for more work ... ! :-)
Re: Back from vacation and 4 new articles online ! :-) - Rodger Rosenbaum - 08-21-2007 In the first paragraph of your new article, "Boldly Going...Matrix Square Root", you say "...nor can programmed solutions be found." You must have missed my post in the thread: http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv014.cgi?read=66526 which contains a programmed solution for the matrix square root problem. It requires the EGV function found on the HP48G and descendants.
The program gets the same solution you do for all your examples.
Re: Back from vacation and 4 new articles online ! :-) - Valentin Albillo - 08-22-2007 Hi, Rodger: Rodger wrote:
Besides, my last posted message in that thread was #21 while your first posted message was #32, so I had already stopped reading the thread by the time you first posted and thus your post went utterly unnoticed by me. "[...] which contains a programmed solution for the matrix square root problem. It requires the EGV function found on the HP48G and descendants."
If that's correct, I think it might be the case that your approach only works for the special case of diagonalizable matrices. All the examples in my article deal with diagonalizable matrices, which explains why you get the same results. It might be the case that for some non-diagonalizable matrix my approach would still work but yours won't.
Re: Back from vacation and 4 new articles online ! :-) - Rodger Rosenbaum - 08-23-2007 Quote: Yes, the HP48 program does require the matrix to be diagonalizable, but even though this is a "special" case, it isn't a rare case. Most matrices that arise from physical problems will be diagonalizable, for example. There is a method which would be applicable to non-diagonalizable matrices. It uses the Schur decomposition, but it is more complicated. The HP48G program I've already given is very short and often will work. While it is possible that your method may work with some non-diagonalizable matrices, it doesn't even work with some diagonalizable matrices that the HP48G program handles properly. Your HP71 program doesn't seem to be able to find a square root of these matrices:
[[ 1 2 3 ] and
[[ -9 2 -6 3 ]
Do you know why? I let it go for 900 iterations for both of them, and there was no sign of convergence.
Re: Back from vacation and 4 new articles online ! :-) - Valentin Albillo - 08-23-2007 Hi, Rodger:
Best regards from V.
Re: Back from vacation and 4 new articles online ! :-) - Rodger Rosenbaum - 08-23-2007 For the first one:
[[ (.449756,.762279) (.552622,.206796) (.655487,-.348687) ] and the second one:
[[ (.215101,2.95788) (-.183078,-.489361) (.215101,1.22583) (.343944,-1.07186) ]
I've only shown 6 digit results, although the calculator returned 12 digits. When the 12 digit results are squared, the error is out in the 11th or 12th place.
Thanks a lot, I'll check it. [NT] - Valentin Albillo - 08-23-2007 Best regards from V.
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