From: SourceForge.net <noreply@so...>  20100129 23:04:09

Bugs item #2942553, was opened at 20100129 23:17 Message generated for change (Comment added) made by crategus You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2942553&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: None Group: None >Status: Pending >Resolution: Invalid Priority: 5 Private: No Submitted By: Dieter Kaiser (crategus) Assigned to: Nobody/Anonymous (nobody) Summary: hgfred([n,n+1],[1],x) not correct Initial Comment: The result of hgfred([n,1+n],[1],x) is not correct. This is what Maxima gives: (%i1) res:hgfred([n,n+1],[1],x); Is x positive, negative, or zero? p; Is x1 positive, negative, or zero? n; (%o1) legendre_p(n1,12*x) The correct result is legendre_p(n, 12*x). For the special values n=1, n=2, n=3, ... Maxima gives the correct results: (%i2) hgfred([1,1+1],[1],x); (%o2) 12*x (%i3) hgfred([2,2+1],[1],x); (%o3) 6*x^26*x+1 (%i4) hgfred([3,3+1],[1],x); (%o4) 20*x^3+30*x^212*x+1 We can not reproduce the correct results, when we insert the special values in the result from above: (%i5) res,n=1; (%o5) 0 (%i6) res,n=2; (%o6) 0 (%i7) res,n=3; (%o7) 0 Furthermore, I think the question for the sign of the argument x is not necessary. The problem is in the algorithm of the routine legf14. Dieter Kaiser  >Comment By: Dieter Kaiser (crategus) Date: 20100130 00:04 Message: Sorry, I have overseen the identity legendre_p(n1,x) = legendre_p(n,x). With this identity the result of hgfred might be not nice, but it is correct. Unfortunately, legendre_p(n1,x) does not simplify to correct values. Perhaps this might be called a bug. Setting the status to pending and the resolution to invalid. Dieter Kaiser  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2942553&group_id=4933 