errors in 3.0(beta) and 2.2
- To: mathgroup at smc.vnet.net
- Subject: [mg5604] errors in 3.0(beta) and 2.2
- From: Jonathan Connor <Jonathan.Connor at nessie.mcc.ac.uk>
- Date: Fri, 27 Dec 1996 01:59:10 -0500
- Sender: owner-wri-mathgroup at wolfram.com
(* It is very easy to get completely wrong results
in both 2.2 and 3.0(beta) using one line examples.
The following example concerns LegendreP[10,10,x]
in 2.2 on a Mac, but I got similar results with
3.0(beta). I noticed the errors when using Plot[]
with LegendreP[10,10,Cos[t*Degree]]
I would appreciate comments, workarounds etc.
Does the released version of 3.0 have these errors?
$Version
Macintosh 2.2 (May 4, 1993)
(* Notice LegendreP[10,10,x] is a simple polynomial
of degree 10 *)
LegendreP[10,10,x]
2 4 6 8 10
654729075 (1 - 5 x + 10 x - 10 x + 5 x - x )
(*The following two results look reasonable *)
LegendreP[10,10,Cos[179*Degree]]//N
-9
2.27155 10
LegendreP[10,10,Cos[t*Degree]]/.t->179.0//N
-9
2.27155 10
(* The next result is wrong *)
LegendreP[10,10,Cos[179.0*Degree]]//N
8
1.02775 10
(* All the following results are wrong *)
LegendreP[10,10,Cos[179.9999*Degree]]//N
48
-2.68317 10
LegendreP[10,10,Cos[179.99999*Degree]]//N
51
4.88061 10
LegendreP[10,10,Cos[179.999999*Degree]]//N
57
4.87838 10
LegendreP[10,10,Cos[t*Degree]]/.t->179.999999//N
0