Crash when Solve for Integral with 15C

08312017, 01:21 PM
(This post was last modified: 08312017 01:46 PM by Gamo.)
Post: #1




Crash when Solve for Integral with 15C
With this integral problem it crash when used the 15C app for Android but 15C Virtual Calculator for Windows PC is running fine and took about almost 1 minute to solve.
I don't have physical HP 15C to try just like to know if it crash that too. To solve: Set the program g P/R f PRGM LBL 0 3 y^x e^x g RTN g P/R To run integral 0 ENTER 6 [f] [∫xy] [0] Answer: 5.9639 91 Link to the clip: https://youtu.be/QiTh7n3wRRE Here is the problem attached as jpg. Gamo 

08312017, 01:27 PM
Post: #2




RE: Crash when Sove for Integral with 15C
(08312017 01:21 PM)Gamo Wrote: With this integral problem it crash when used the 15C app for Android but 15C Virtual Calculator for Windows PC is running fine and took about almost 1 minute to solve. For reproducing/testing a bug, please provide the exact program/entry steps you used. It can be done more than 1 way, and the problem may be related to how you entered it. Bob Prosperi 

08312017, 05:44 PM
(This post was last modified: 08312017 05:45 PM by SlideRule.)
Post: #3




RE: Crash when Solve for Integral with 15C
Gamo
The integral is discussed quite well at How to Evaluate e^x^3 BEST! SlideRule ps: it crashes a Casio as well 

08312017, 06:34 PM
(This post was last modified: 08312017 06:42 PM by Gilles59.)
Post: #4




RE: Crash when Solve for Integral with 15C
After à long time i get "pr error" with the HP15cle (but im a poor user with the 15c perhaps i do something wrong)
Works fine on the 50g 

08312017, 07:09 PM
(This post was last modified: 08312017 07:13 PM by BobVA.)
Post: #5




RE: Crash when Solve for Integral with 15C
(08312017 06:34 PM)Gilles59 Wrote: After à long time i get "pr error" with the HP15cle That's a "power error", so perhaps the batteries are getting a bit low and the long run time dragged them down far enough to cause a reset? [Not a direct answer to the OP's question, but my LE was also taking *quite* awhile to run this, so I replaced the initial exponentiation with two multiplications. It still took about five minutes to produce the same result noted in the original post. Maybe you can try this in the app? That might at least narrow down where the problem is occurring?] Bob 

08312017, 08:55 PM
(This post was last modified: 08312017 09:14 PM by SlideRule.)
Post: #6




RE: Crash when Solve for Integral with 15C
Gamo
From the aforementioned url: "It is very common for an elementary function not to have an elementary antiderivative. Proving this is the case for a particular function can be difficult. Your function e^x^3 happens to be one for which the standard method for showing "impossibility," which dates back in principle to Liouville, works reasonably smoothly. Many nonelementary "special functions" have been devised such that useful integrals can be expressed in terms of these special functions. I would guess that Maple, or Mathematica, even Wolfram Alpha, can produce an answer in terms of some special function." from Wolfram Alpha [attachment=5146] "The antiderivative of e^x^3 cannot be expressed in terms of elementary functions. We can, however, express it using power series... another try you can solve it with Gamma function... finally ... The integral cannot be evaluated. We have to use power series of exponent and then integral term by term., or use a substitution. BEST! SlideRule 

08312017, 10:39 PM
(This post was last modified: 08312017 11:24 PM by rprosperi.)
Post: #7




RE: Crash when Solve for Integral with 15C
Gamo,
Thanks for the program steps. Which 15C Virtual Calculator are you using on Windows? I've tested it on Torsten Manz' 15C simulator running on Win7 and on a SwissMicros DM15L. Both are still "running" after well more than 5 minutes. No crash or error messages, they're just running and running. I got tired of waiting so added this reply. I'll update with results if anything ever appears. Update: They just kept on running... with no anwer. While waiting , I also tried it in the DM42 and it got the same answer in 23 seconds. Bob Prosperi 

09012017, 01:35 AM
Post: #8




RE: Crash when Solve for Integral with 15C
Hello rprosperi
I'm using the original HP 15C Virtual Calculator from HP for Windows PC this is the only one that run through without any problem in about 1 minute. I did try this on HP Prime App for Android and it crash when execute in Home mode. On CAS mode the error message appear and gave the answer instantly. HP Prime Virtual Calculator for Windows PC also crash and the application close altogether. Gamo 

09012017, 01:40 AM
(This post was last modified: 09012017 02:49 PM by SlideRule.)
Post: #9




RE: Crash when Solve for Integral with 15C
Gamo
Perhaps this attached GRAPH will help? [attachment=5148] or the following url Functions without Antiderivatives by TR Smith with the follwing extract: "Exponential Functions Here is a list of basic exponential forms that have no antiderivatives • e^(x^2) and e^(x^2) • e^(x^3) and e^(x^3) • More generally, e^(x^n) and e^(x^n) are nonintegrable for all integers n greater than 1. • e^(1/x) and e^(1/x) (See link for approximate integration technique.) • e^(1/x^2) and e^(1/x^2) • More generally, e^(1/x^n) and e^(1/x^n) are non integrable for all positive integers n." BEST! SlideRule 

09012017, 03:27 AM
Post: #10




RE: Crash when Solve for Integral with 15C  
09012017, 05:47 AM
(This post was last modified: 09012017 05:50 AM by Dieter.)
Post: #11




RE: Crash when Solve for Integral with 15C
(09012017 01:40 AM)SlideRule Wrote: Perhaps this attached GRAPH will help? Yes, the function has no closed form antiderivative. But that does not matter here because the 15C is calculating a definite integral by numeric integration. Exactly because there is no analytic solution. ;) For the math geeks: somehow I feel that in this case some variable substitution should be applied to calculate the integral easier and faster. Maybe someone has an idea here? Dieter 

09012017, 10:30 AM
(This post was last modified: 09012017 10:46 AM by SlideRule.)
Post: #12




RE: Crash when Solve for Integral with 15C
(09012017 05:47 AM)Dieter Wrote: For the math geeks: somehow I feel that in this case some variable substitution should be applied to calculate the integral easier and faster. Maybe someone has an idea here?Perhaps post#3, #6 or #9? BEST! SlideRule ps: there is an excellent paper Nonelementary Antiderivatives by Dana P. Williams (Dartmouth college) with specific reference to e^x^2: a good read & very edifying! 

09012017, 11:51 AM
Post: #13




RE: Crash when Solve for Integral with 15C
\(5.963938091897677519629320420205\underline{665}×10^{91}\) in a wp34s after 2'20''.
\(5.9639×10^{91}\) in a DM15L after 50'. 

09012017, 01:24 PM
Post: #14




RE: Crash when Solve for Integral with 15C
(09012017 11:51 AM)emece67 Wrote: \(5.9639×10^{91}\) in a DM15L after 50'. Ah, I see. I guess I'm not patient enough; If only I waited 20 more minutes, I could have posted this first, lol. Bob Prosperi 

09012017, 02:14 PM
Post: #15




RE: Crash when Solve for Integral with 15C
(09012017 01:24 PM)rprosperi Wrote:(09012017 11:51 AM)emece67 Wrote: \(5.9639×10^{91}\) in a DM15L after 50'. Less than 2 and a half minutes here: 5.963938096E91 (FIX 9) HP15C Emulator for iOS by HP LBL 0 x^2 * e^x RTN Not patient enough to try it on the HP15C LE, though. Gerson. 

09012017, 05:36 PM
(This post was last modified: 09012017 05:38 PM by emece67.)
Post: #16




RE: Crash when Solve for Integral with 15C
(09012017 01:24 PM)rprosperi Wrote:(09012017 11:51 AM)emece67 Wrote: \(5.9639×10^{91}\) in a DM15L after 50'. Sorry, it should be: \(5.9639×10^{91}\) in a DM15L after 50''. My DM15L was running at 48 MHz. If switched to 12 MHz it takes around 3 minutes. 

09022017, 02:41 AM
Post: #17




RE: Crash when Solve for Integral with 15C
(09012017 05:36 PM)emece67 Wrote: Sorry, it should be: I just tried again, and again my DM15L ran for 10 minutes with no result. Then it occurred to me that I was running in FIX 2 mode, which could be affecting behavior. So I changed display mode to SCI 4, and I then got the same result in about the same time as your results. Though it is specifically discussed, the manual is not completely clear (to me) about how display mode affects results, but it seems to have a dramatic impact. I would expect a setting with 2 digits of accuracy (FIX 2) would have finished faster than with 4 (SCI 4) since even when set to FIX mode, it switches to SCI mode as needed if the magnitude under/overflows. Perhaps some of the other error and/or endless calculating errors reported above were also affected by the same issue. Try again using SCI 4 mode. Thanks for the correction emece67; it motivated me to explore this further and learn a bit in the process. Bob Prosperi 

09022017, 05:53 AM
(This post was last modified: 09022017 05:54 AM by Dieter.)
Post: #18




RE: Crash when Solve for Integral with 15C
(09022017 02:41 AM)rprosperi Wrote: Though it is specifically discussed, the manual is not completely clear (to me) about how display mode affects results, but it seems to have a dramatic impact. Yes. Maybe you should take a look at the respective section in the 15C Advanced Functions Handbook. (09022017 02:41 AM)rprosperi Wrote: I would expect a setting with 2 digits of accuracy (FIX 2) would have finished faster than with 4 (SCI 4) since even when set to FIX mode, it switches to SCI mode as needed if the magnitude under/overflows. The result is about 6 E+91. FIX 2 means two digits after the decimal point, so that's actually 94 significant digits, in other words: it's (more than) full machine precision you're demanding. On the other hand SCI 4 sets only five significant digits which is returned much faster. (09022017 02:41 AM)rprosperi Wrote: Perhaps some of the other error and/or endless calculating errors reported above were also affected by the same issue. Try again using SCI 4 mode. Yes, for a first result I'd say even SCI 2 is fine. If you need more simply repeat the calculation with SCI 4, SCI 6 etc. Dieter 

09022017, 06:48 AM
(This post was last modified: 09022017 06:51 AM by Gerson W. Barbosa.)
Post: #19




RE: Crash when Solve for Integral with 15C
(09012017 05:47 AM)Dieter Wrote: somehow I feel that in this case some variable substitution should be applied to calculate the integral easier and faster. Maybe someone has an idea here? By making u=x^3 the integral can be evaluated twice as fast on the HP15C emulator: 2 ENTER 3 / STO 0 LBL 0 e^x LASTx RCL 0 y^x / RTN 0 ENTER 216 Intxy 3 / => 5.963938097E91 (1'15") Gerson. 

09022017, 08:37 AM
(This post was last modified: 09022017 08:47 AM by Vincent Weber.)
Post: #20




RE: Crash when Solve for Integral with 15C
Various tests in SCI 4 mode of the original program posted:
HP app on Android: straight crash of the app. Well done, HP, with your own material. We know that the HP way is dead... HP app on iOS, latest beta (I am part of the beta program): surprisingly better, returns the correct answer in a few seconds... But strangely, the LCD is blinking, as if an error has occured.. Olivier de Smet's go15c on Android at max speed: correct answer in 2 seconds, no blinking. None of these behave well in FIX 9 mode. The HP Android app still crashes immediately. The other too seem to run forever even go15c in max mode. Trying now on a real 15C (the original, not the buggy LE) will revert. Cheers 

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