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?
Simplify with sci/eng on hp 50g
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11-06-2012, 04:38 AM
11-06-2012, 05:37 PM
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
11-06-2012, 06:37 PM
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).
11-06-2012, 06:50 PM
I have made a recording of this in the emulator: http://www.mediafire.com/?9cnml3z1c3yvhw8
11-07-2012, 06:15 AM
Hi Juraj,
Edited: 7 Nov 2012, 6:48 a.m.
11-07-2012, 10:56 AM
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.
11-07-2012, 11:25 AM
How do you do ? In RPN mode I get the right answer
11-07-2012, 11:39 AM
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.
11-07-2012, 11:44 AM
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.
11-08-2012, 10:34 AM
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.
11-08-2012, 06:26 PM
I can also confirm this behavior on the HP50G ROM 2.15 Han
11-16-2012, 07:24 PM
Quote: It looks like my physical calculator does have this issue. Maybe I should try to install an older version? |
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