Bugs in Mma functions on the NeXT
- To: mathgroup at yoda.physics.unc.edu
- Subject: Bugs in Mma functions on the NeXT
- From: herrmann at siam.math.tamu.edu (joe herrmann)
- Date: Wed, 10 Feb 1993 17:07:27 -0600
Dear Mathgroup,
I installed Mma 2.1 for the NeXT which I ran under NeXTStep OS 2.1 to
fix the bugs in Mma 2.0 that E^(-625000)= 1.40101 10^22, E^(-670000)=
2.51105 10^56, etc. Mma 2.1 fixed these particular values and others I
identified but I have found the values given below are still incorrect
in Mma 2.1 under NeXTStep OS 2.1. However all exponential bugs I am
aware of are fixed in Mma 2.0 or 2.1 by upgrading to NeXTStep OS 3.0.
However, I found a bug in BesselJ in 3.0 as can be seen in the
following: BesselJ[177.4,28.-.28I]=0. + 0. I and
BesselJ[177.4,28.]=0. The first is definitely wrong since all zeros
of BesselJ with order greater than -1 are real, moreover for Mma 2.0 on
NeXT OS 2.1 and for Mathematica (MIPS) I find
-121
BesselJ[177.4,28.]= 2.513042235631 10
-122 -121
BesselJ[177.4,28.-.28I]= -4.56550333659 10 - 2.49427565746 10 I
Exponential bugs in Mma 2.1 under NeXTStep OS 2.1:
Table[{x,N[E^x]},{x,-300000,-200000,5000}]
-130289
{{-300000, 4.5230253774 10 },
-71
{-295000, 4.1807 10 },
-125946
{-290000, 3.9833462329 10 },
-102060
{-235000, 6.2625720561 10 },
-296
{-230000, 1.05042 10 },
-97717
{-225000, 5.5153333723 10 },
Sincerely,
Joe Herrmann
Texas A&M Math Dept
herrmann at siam.tamu.edu