At 04:34 AM 3/18/2007 +0000, [EMAIL PROTECTED] wrote: >Do 'human rounding principles' say that you would expect 10 / 3 rounded >to 2 DP would produce 3.34 or 3.33? How about -10 / 3?
10/3 rounded to two places is 3.33. 3.34 is simply wrong. To say that 3.34 is 10/3 rouned to two places means that ur using another rounding scheme that people don't use. Same with -10/3. >I assume that if you asked someone to calculate the digits of pi, you'd >expect them to stop some time. How do 'human rounding principles' say >they should deal with that. There's no rounding involved when u stop a calculation. If u calculate pi to 100 digits and stop, the 100th digit has not been rounded. If u wanted to round that to 90 digits then that's rounding. The criteria is pick the value that has the least error from the actual value. >My point was just that I can't think of a single practical case where >you would be worried about whether 1.5 displayed as 1 or 2, and floating >point numbers would have any place in your calculation. If your floating >point answer is crud, then fiddling with it at the end of your >calculation so it looks pretty just makes it cruddier. Rounding to an integer is just the current example. Rounding is usually done to 2-3 places because that's all the precision most things need. A case where rounding makes a huge difference is in estimating. If u round wrong ur estimate will be no good. Usually though rounding is just for human convenience. -- REMEMBER THE WORLD TRADE CENTER ---=< WTC 911 >=-- "...ne cede malis" 00000100 _______________________________________________ Perl-Win32-Users mailing list [email protected] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
