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Simplify with sci/eng on hp 50g - 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: Simplify with sci/eng on hp 50g (/thread-233668.html) |
Simplify with sci/eng on hp 50g - Juraj O. - 11-06-2012 When I change into engineering/scientific mode with a precision of e.g. 1 digit, '70E-9 *cos(0)' gets simplified into 1/e^16 (cas is set to exact). What is going on here?
Re: Simplify with sci/eng on hp 50g - Crawl - 11-06-2012 I am unable to reproduce your error. I get 7.0E-8 A couple of questions: -In the answer, is that e the normal (2.71828...) e? -Do you have E defined to be a variable with a value? -Can you explain *exactly* what you're doing? Example, I am in RPN mode, enter 70E-9 *cos(0) in single quotes, and hit EVAL (or simplify, whatever) and get 7.0E-8
Re: Simplify with sci/eng on hp 50g - Juraj O. - 11-06-2012 Set mode to engineering with precision 1, cas mode exact. Open equation editor, enter cos(0) * 0.01 (another example). Select whole expression and simplify it, or close the equation editor and invoke SIMPLIFY (EVAL does not exhibit this behaviour). It gets simplified to 1/e^5 (yes, that's e, the exponential function).
Re: Simplify with sci/eng on hp 50g - Juraj O. - 11-06-2012 I have made a recording of this in the emulator:
http://www.mediafire.com/?9cnml3z1c3yvhw8
Re: Simplify with sci/eng on hp 50g - Bart (UK) - 11-07-2012 Hi Juraj,
Edited: 7 Nov 2012, 6:48 a.m.
Re: Simplify with sci/eng on hp 50g - Juraj O. - 11-07-2012 In approx mode, 1•0.01 gets simplified right into 6.7E-3. This is really dangerous! How the hell did not anyone discover this earlier? That was on my 3rd or 4th day of owning a 50g.... Edited: 7 Nov 2012, 10:59 a.m.
Re: Simplify with sci/eng on hp 50g - Gilles Carpentier - 11-07-2012 How do you do ?
In RPN mode I get the right answer
Re: Simplify with sci/eng on hp 50g - Bart (UK) - 11-07-2012 Quote:Hi Gilles, v2.09 does get the right answer, but v2.15 gets the answer that Juraj noted. (we are talking about SIMPLIFY command with low digit ENG/SCI/FIX mode). Edited: 7 Nov 2012, 11:52 a.m.
Re: Simplify with sci/eng on hp 50g - Bart (UK) - 11-07-2012 Quote:I guess most users like lots of numbers and do not normally use the SIMPLIFY function with such low digit requirements. Quote:It still seems to try and use the Exact techniques (in Exact mode it gives 1/e^5, which = 6.7E-3 with "-> NUM" in FIX 1). When entering it as '1·(1/100)' the correct answer is produced. It seems to try and find the nearest answer representable with e. I tried several flag settings, but nothing seems to help. Perhaps others have better ideas. As I said, it seems something here broke between v2.09 and 2.15.
Edited: 7 Nov 2012, 12:06 p.m.
Re: Simplify with sci/eng on hp 50g - Crawl - 11-08-2012 Interesting. I tested this on a emulator, though, which would have been an older version. I left my physical HP50g at home, so I'll have to check this on that later.
Re: Simplify with sci/eng on hp 50g - Han - 11-08-2012 I can also confirm this behavior on the HP50G ROM 2.15
Han
Re: Simplify with sci/eng on hp 50g - Crawl - 11-16-2012 Quote:
It looks like my physical calculator does have this issue. Maybe I should try to install an older version?
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