Re: Why Mathematica does not issue a warning when the calculations are losing so much precision that the results are not anymore useful?
- To: mathgroup at smc.vnet.net
- Subject: [mg117549] Re: Why Mathematica does not issue a warning when the calculations are losing so much precision that the results are not anymore useful?
- From: DrMajorBob <btreat1 at austin.rr.com>
- Date: Tue, 22 Mar 2011 05:08:52 -0500 (EST)
That IS an odd result! You probably wanted something like N[FractionalPart[(6 + Sqrt[2])^20], 20] 0.68777820338201214768 Bobby On Mon, 21 Mar 2011 06:13:24 -0500, John Travolta Sardus <pireddag at hotmail.com> wrote: > With Mathematica 8.0.1 > > N[FractionalPart[(6 + Sqrt[2])^20]] > > Result: > > -160. > > Is it a problem for all numerical software being able to recognize when > these calculations cannot be performed with the given machine accuracy? > Does this happen in this case only (where a wrong result is easily > recognized) or in other cases too? > > Thanks for any answer, > > Giovanni > -- DrMajorBob at yahoo.com