+- HP Forums (https://www.hpmuseum.org/forum)
+-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html)
+--- Forum: HP Prime (/forum-5.html)
+--- Thread: Python round() broken (/thread-16682.html)
Python round() broken - Guenter Schink - 04-17-2021 07:08 PM
Is it just my G2 to show this error in Python?
round(3/7,6) ==> 0.4285709999999999 (if I counted the 9s correctly)
should be 0.2428571
similar error with
round(5/7,6)
round(3/11,6)
round(5/11,6
round(7/11,6)
previously in my post a first digit "2"crept in inadvertently
The virtual calculator 64bit doesn't show this behavior.
Günter
PS: of course reported to calcbeta too
RE: Python round() broken - toml_12953 - 04-17-2021 08:48 PM
(04-17-2021 07:08 PM)Guenter Schink Wrote: Is it just my G2 to show this error in Python?
round(3/7,6) ==> 0.24285709999999999 (if I counted the 9s correctly)
should be 0.2428571
Wow! Your calculator is really off! I get
0.4285709999999999
RE: Python round() broken - Guenter Schink - 04-17-2021 11:10 PM
(04-17-2021 08:48 PM)toml_12953 Wrote:(04-17-2021 07:08 PM)Guenter Schink Wrote: Is it just my G2 to show this error in Python?
round(3/7,6) ==> 0.24285709999999999 (if I counted the 9s correctly)
should be 0.2428571
Wow! Your calculator is really off! I get
0.4285709999999999
grrr.. typo - first digit "2" shouldn't be there. But what would you expect with rounding to 6 digits? The result should be 0.428571
Günter
RE: Python round() broken - toml_12953 - 04-18-2021 12:32 AM
(04-17-2021 11:10 PM)Guenter Schink Wrote:Yes, You added an extra 2. I knew that it wasn't your calculator, hence the smiley.(04-17-2021 08:48 PM)toml_12953 Wrote: Wow! Your calculator is really off! I get
0.4285709999999999
grrr.. typo - first digit "2" shouldn't be there. But what would you expect with rounding to 6 digits? The result should be 0.428571
Günter
RE: Python round() broken - cyrille de brébisson - 04-19-2021 09:48 AM
Hello,
I have literally NO clue as to what is going on there!
Works on emulator, works on prime G1... but prime G2 fails!
Something buried deep in the float library or something like that?
Note that Python uses doubles... As such, these are binary numbers... not BCD... so things like rounding will/Can yeild unexpected results...
Cyrille