Mathematica 1.2 bug in BesselI[nu,x] with nu > 20 and nu ~ 1.5x
- To: mathgroup at yoda.physics.unc.edu
- Subject: Mathematica 1.2 bug in BesselI[nu,x] with nu > 20 and nu ~ 1.5x
- From: "NELSON M. BLACHMAN" <blachman at gtewd.mtv.gsc.gte.com>
- Date: Thu, 24 Sep 1992 16:15:50 PDT
I've just noticed that Mma 1.2 gives BesselI[44,30.] = 0. and
BesselI[60,40.] = 0., with even more peculiar (frighteningly large |values|)
for indexes and arguemnts in these neighborhoods. For larger arguments,
Mma 1.2 apparently satisfactorily uses the asymptotic series and for indexes
under 21 it seems OK. It would be good to know just when it can be trusted. .
In Mma 2.0 this BesselI bug has apparently been corrected, but those who
may have used or may use Mma 1.2 programs involving numerical values of
BesselI[nu,x] with nu > 20 should be warned not to trust the results without
thorough checking.
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