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From: Michael Kuyumcu on 3 Sep 2006 14:25 Hi Yao, I just tested: o "seq(seq(1/(sqrt(2*i+1-I*(3*j+2))),i,1,3),j,1,3)^-1", which yields "Singular matrix", and then o "seq(seq(1/(sqrt(2*i+1)+I*sqrt(3*j+2)),i,1,3),j,1,3)^-1", and again: "Singular matrix". I havent's double-checked with the hp49g+ whether or not this matrix is in fact singular, but if not, we might have hit on a CAS error. Regards, Michael Yao Konan schrieb: > Hi Michael, > > Michael Kuyumcu a écrit : > > > Hi, > > > > I just retried > > "seq(seq(1/(sqrt(2*i+1)+I*sqrt(2*j+1)),i,1,4),j,1,4)^-1", and now it > > works, except that the calc answers with "Errro: singular matrix" after > > a second or so. The same error message is given for > > "seq(seq(1/(sqrt(2*i+1)+I*sqrt(2*j+1)),i,1,3),j,1,3)^-1". Is this a > > singular matrix? Well, let's see: > > > > > I evaluated: > > "seq(seq(1/(sqrt(2*i+1)+I*sqrt(2*j+1)),i,1,3),j,1,3)" > > (the result was there in a fraction of a second) > > and then > > "det(ans)" > > which yielded "0" > > Doesn't seem to look like a singular matrix but my TI92+ fails to > compute the determinant after over hour so i cancel the > operation.However in approximate mode,it does return a non null complex > expressions. > > > So if the determinant determination algorithm works correctly, this > > indeed is an impossible problem. > > So we could try with a slighty modifier matrix such as: > seq(seq(1/(sqrt(2*i+1-I*(3*j+2))),i,1,3),j,1,3) which certainly not > singular and which seems to give even more trouble to the TI92+. > > > When I want to find out how long a certain operation takes, can I use > > any TIMING measuring function? I haven't found anything in the PC > > software reference guide which claims to be 100% compatible. Do you > > know of any method? > > There is one on the TI89T/Voyage 200. > startTmr()->chrono: > Computation: > checkTmr(chrono) > The last instruction will return the timing of the Computation in > seconds. > However it remains to be seen if it works on the TI-Nspire. > > > There is no "variable manager", no. > > So it shouldn't be easy to manage variables within a document. > > > "approx(randmat(60,60))" still works, > > so the mentioned memory limit seems to have been removed. > > It seems so.That would explain why some operations which returns a > memory error on the > TI92+ doesn't do the same on the TI-NSpire. > > > Do you happen to know whether there are user-written or commercial > > packages available for the TI-92 or Voyage series that do > > multiple-precision math on floating point numbers (like with 900 digits > > or such) written in machine language? I find it extremely limited that > > the nspire fails to calculate 300!, and does not support any floats > > with more than 14 digits (internally up to 17). Booooh! > > Unfortunately i am not aware of any match package which add arbitrary > floating point number as well as virtually unlimited number arithmetic > on the TI92 series. > All math packages i know deal with the built-in number arithmetic and > just add functionnality to the calculators. > However if TI want seriously to replace Derive with the TI-NSpire,they > will have to remove all these kinds of limitations. > > > > Regards, > > Michael Kuyumcu > > Best regards.
From: Michael Kuyumcu on 3 Sep 2006 14:34 Arbitrary precision numbers on the HP? I am aware only of *integers* with multiple precision. Why didn't HP follow through on implementing multiple-precision arithmetic also for floats? Now that the basic routines are in place, it just needs consideration of the decimal point... That's really poor calculus design (as on the TIs). Michael Kuyumcu Steen Schmidt schrieb: > Paul Schlyter wrote: > > > > You can do games and such, but when you need to do some data IO with > > > the OS (even a plotter app does that), you're bound by the > > > limitations of the existing OS (data types, argument ranges, file > > > structure etc). > > > > If you do C/C++ without any OS, you have no such limitations. I mean, > > in such a situation there is no OS; so how could a non-existent OS > > limit you? > > What would you do when you have calculated 10000! ? Would you display > the 35660 digits on the screen for the user to decipher one at a time? > What if the result was to be used by a subsequent calculation? Or let's > say you coded a new symbolic integration engine in C - how would you > output the integral of 'Exp(X^2),X'? The result is > '1/2*Sqrt(pi)*Erfi(X)', but Erfi(X) isn't defined in the TI AMS. You > could code Erfi(X) in C, but the result had to reside temporarily in > the TI OS environment, until the user decides to do something else with > the result (evaluate it numerically or integrate it again etc.). What > object type would Erfi(X) be in this case, inside the TI AMS? > > The OS (and its aux sw like parsers, type checkers, CAS etc.) limits > you in what you can return to it or get as arguments from it. On the HP > we have built-in data types for arbitrary precision numbers, arrays of > any type etc. There are libraries with support for user-defined > functions that behave exactly like built-in functions. This is not the > case on the TI - not even on the NSpire. The latter I find > disappointing, as it would be a good time to step up from the silly > limitations of the TI92/92+/V200/89/89ti series. > > But TI will probably not do this, as the open structure of the HP OS > opens up for a hornets nest of bug possibilities. If you look at how > flexible the HP OS is - how much is available for the user - then it's > obvious that there's much greater risk of bugs existing therein in > comparison with the closed TI OS. > > All the above is moot of course, in the event you'd want to code your > own OS in C/C++. And even in that case, it would probably have to be > done over a couple of times, as you'd probably not succeed in putting > in all the features another programmer wished for, in which case that > other programmer had to code his or her own special OS etc... > > Regards > Steen
From: Michael Kuyumcu on 3 Sep 2006 14:37 No "setmode()" possible. Unknown to the nspire. Michael Kuyumcu Yao Konan schrieb: > If it is possible to plot 3D graph this command should enabe it,if the > NSpire behaves like the TI92: > setmode("Graph","3D"):Graph (x^3*y-y^3*x)/390 > > Michael Kuyumcu a écrit : > > > Is there a quick way to test 3D functions plotting capabilities. I > > mean, now that we know that programming constructs work in functions, > > maybe you could come up with 4 or 5 lines of test codes for 3D > > plotting? Of course, I don't know whether that kind of programming > > would be so easy, but if it is, maybe you would like to try it? > > > > Anyway, thanks for considering it! > > > > Regards, > > Michael Kuyumcu > > > > > > > > > > Yao Konan schrieb: > > > > > Thanks for the information. > > > It is surprising that 3D plotting is not easily availlable as it is one > > > of my favorite feature of those advanced calc and in fact one of the > > > main marketing argument for the TI92 when it was introduced in 1995. > > > For programming of the Tool assuming that it has a similar user > > > language to the TI92,you can find some help from the TI89TI/Voyage 200 > > > guidebook availlable from the TI site here: > > > http://education.ti.com/educationportal/appsdelivery/download/download_eula.jsp?cid=us&displayMode=G&applicationid=6128&contentpaneid=17 > > > > > > Eventually i could give you additionnal help if needed as i happen to > > > be quite strong with TI92 Basic. > > > I think that you could write programs with the Note editor then > > > tokenize and save them from the calculator screen. > > > For exemple the famous Hello world: > > > Define hello()=Prgm: > > > Text "Hello Wolrd":EndPrgm > > > Execute from the calculator apps,this should create the program which > > > when called as > > > hello() should show a window with the message. > > > > > > Michael Kuyumcu a écrit : > > > > > > > Hi Jean-Yves, > > > > > > > > no touch sreen, just a small circular plastic pad which is sensitive to > > > > finger presses and with which you can push the pointer arrow on the > > > > screen into any direction (diagonally works, too). There are additional > > > > arrow keys which basically do the same thing but much more slowly > > > > (pixel-wise). The pointer speed is ok now, but will be too slow when I > > > > have gotten used to it, I think. There is no way to change the speed, > > > > although there are a couple of other general "system settings". The > > > > device is completely menu-driven, just like any ordinary PC, you can > > > > have any number of documents open at one time, among them a > > > > spreadsheet, which is much like Excel. It features local and global > > > > cell references, and the whole apparatus for symbolic math (the CAS > > > > core) can be used in any cell. There is an automated sequence generator > > > > for the spreadsheet, too, which is nice when doing pseudo-random test > > > > series. The basic principle is that you have a "problem" (that's how TI > > > > calls the Nspire documents, I hope the docs won't cause any) to which > > > > you can assign up to four different applications (CAS, graphics, > > > > spreadsheet, and notes). Changes in variables, definitions and so forth > > > > in any of the environments immediately and dynamically affect all > > > > assigned applications. > > > > > > > > In fact, I like the device a lot so far. It features a big clear > > > > screen, which is just a tad too dark for me and could have been coated > > > > in a way to better prevent light reflections. It seems to be > > > > programmable (there are flow control constructs, Goto Label command, > > > > and the like). I just have not written any program yet, and don't know > > > > how to (where to write it and how to run it and so on), since there is > > > > no written documentation with the calculator, and the last TI I have > > > > programmed was the TI 66. In fact, I learned programming on that > > > > calc... nostalgia... Can anyone point me to programming ressources for > > > > the Voyage or the TI-92? Maybe the systems will turn out to be similar. > > > > I have not noted any options for assembler programming (which is one of > > > > my favorite pastimes). > > > > > > > > I have found numerous graphics plotting capabilities, but none dealing > > > > with 3D so far. But then, I had the Nspire running for only 30 minutes > > > > roughly yet. > > > > > > > > Regards, > > > > Michael Kuyumcu > > > > > > > > > > > > > > Hi Michael. > > > > > > > > > > Thank you for your post. > > > > > > > > > > It looks like TI made the best use of the waiting time and created a > > > > > learning device similar to what Xpander should have been. > > > > > Is the calculator using a touch screen or like what it appears on photo > > > > > just a little joystick? if yes, how does it work? do you like it? > > > > > > > > > > Does it have a spreadsheet? how does it work? > > > > > > > > > > > > > > > Too bad HP was left behind technologically. I agree with your earlier > > > > > comments. > > > > > > > > > > Jean-Yves
From: Yao Konan on 3 Sep 2006 15:02 Hi Michael, Have you tried in approx mode ? Because on my TI92+ both matrix(especially the first one) don't look singular in approx mode. The determinant computations take too much time. Regards, Konan Yao Michael Kuyumcu a écrit : > Hi Yao, > > I just tested: > o "seq(seq(1/(sqrt(2*i+1-I*(3*j+2))),i,1,3),j,1,3)^-1", which yields > "Singular matrix", and then > o "seq(seq(1/(sqrt(2*i+1)+I*sqrt(3*j+2)),i,1,3),j,1,3)^-1", and again: > "Singular matrix". > I havent's double-checked with the hp49g+ whether or not this matrix is > in fact singular, but if not, we might have hit on a CAS error. > > Regards, > Michael > >
From: Steen Schmidt on 3 Sep 2006 15:51
Michael Kuyumcu wrote: > Arbitrary precision numbers on the HP? I am aware only of integers > with multiple precision. Why didn't HP follow through on implementing > multiple-precision arithmetic also for floats? The data type is built-in for arbitrary floating point real and complex numbers (type 27). If you install the Longfloat library you also have arbitrary floating point arithmetic at your fingertips (using that built-in datatype). Pi to 200 decimal places in 2.5 seconds for instance. And that is not in C. Regards Steen |