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Student Support Forum: 'RootReduce[] is buggy (Win98, Mma 3.0.1.1x)' topicStudent Support Forum > General > Archives > "RootReduce[] is buggy (Win98, Mma 3.0.1.1x)"

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Author Comment/Response
Shawn Cokus
01/21/00 08:43am

From a clean slate (Windows 98, Mathematica 3.0.1.1x):

SetOptions[Root, ExactRootIsolation->True];
RootReduce[1-Root[(#^4 - 2) &, 1]^2]

...gives the error: ''General::ivar : Sqrt[2] is not a valid variable.'' (But answer 1-Sqrt[2] is correct.)

From a clean slate (Windows 98, Mathematica 3.0.1.1x):

SetOptions[Root, ExactRootIsolation->True];
RootReduce[1-Root[(#^4 + 1) &, 1]^2]

...gives the error: ''Part::partd : Part specification I[[2]] is longer than depth of object.'' (But answer 1-I is correct.)

Given that ExactRootIsolation->True is supposed to make things completely *rigorous* (and is necessary once the algebraic degrees get high enough), these obvious errors inside RootReduce[] or Root[] or other internals are not encouraging, to say the least.

I guess I'm expecting to hear whether this behavior is a reproducible bug by others, and what the status of the problem is: will it ever affect the correctness of the result?

Thanks,
--Shawn.

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Subject (listing for 'RootReduce[] is buggy (Win98, Mma 3.0.1.1x)')
Author Date Posted
RootReduce[] is buggy (Win98, Mma 3.0.1.1x) Shawn Cokus 01/21/00 08:43am
Re: RootReduce[] is buggy (Win98, Mma 3.0.1.1x) Forum Modera... 01/21/00 08:47am
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