## maxima-bugs

 [Maxima-bugs] [ maxima-Bugs-1215067 ] hgfred([1,1],[1/2],x) From: SourceForge.net - 2005-06-05 07:52:26 ```Bugs item #1215067, was opened at 2005-06-05 02:52 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1215067&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: Lisp Core Group: None Status: Open Resolution: None Priority: 5 Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: hgfred([1,1],[1/2],x) Initial Comment: I think hgfred([1,1],[1/2],x) evaluates incorrectly. Consider: The rising factorial (%i1) rf(x,n) := product(x+i,i,0,n-1)\$ The sum of the first three terms of 2F1 (%i2) f21(a,b,c,x) := sum(rf(a,i) * rf(b,i) * x^i/(i ! * rf(c,i)),i,0,2)\$ Let's taylor hgfred([1,1],[1/2],x) (%i3) taylor(hgfred([1,1],[1/2],x),x,0,2); (%o3) 1+(3*x)/4+(3*x^2)/4+... Compare with f21(1,1,1/2,x) (%i4) f21(1,1,1/2,x); (%o4) (8*x^2)/3+2*x+1 They disagree. Try different parameters -- this time they agree (%i5) taylor(hgfred([1,2],[3],x),x,0,2); (%o5) 1+(2*x)/3+x^2/2+... (%i6) f21(1,2,3,x); (%o6) x^2/2+(2*x)/3+1 This might be a bug in taylor. But I doubt that -- commercial macsyma's value for hgfred([1,1],[1/2]) differs from the one given by maxima (D5) asin(sqrt(x))*sqrt(x)/(1-x)^(3/2)+1/(1-x) (%i7) build_info(); Maxima version: 5.9.1 Maxima build date: 7:34 9/24/2004 host type: i686-pc-mingw32 lisp-implementation-type: Kyoto Common Lisp lisp-implementation-version: GCL 2.6.5 Barton ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1215067&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-1855115 ] hgfred([1],[2],x) From: SourceForge.net - 2007-12-20 19:29:04 ```Bugs item #1855115, was opened at 2007-12-20 13:29 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1855115&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: Open Resolution: None Priority: 5 Private: No Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: hgfred([1],[2],x) Initial Comment: A&S 13.6.13 tells us that 1F1(1,2,x) = 2 * exp(x/2) * sinh(x/2) / x but (%i72) hgfred([1],[2],x); (%o72) (sqrt(%pi)*bessel_i(1/2,x/2)*%e^(x/2))/sqrt(x) I think (%o72) isn't wrong, but I don't think it's what we want. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1855115&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-1855115 ] hgfred([1],[2],x) From: SourceForge.net - 2007-12-21 00:30:10 ```Bugs item #1855115, was opened at 2007-12-20 14:29 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1855115&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: Lisp Core Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: hgfred([1],[2],x) Initial Comment: A&S 13.6.13 tells us that 1F1(1,2,x) = 2 * exp(x/2) * sinh(x/2) / x but (%i72) hgfred([1],[2],x); (%o72) (sqrt(%pi)*bessel_i(1/2,x/2)*%e^(x/2))/sqrt(x) I think (%o72) isn't wrong, but I don't think it's what we want. ---------------------------------------------------------------------- >Comment By: Raymond Toy (rtoy) Date: 2007-12-20 19:30 Message: Logged In: YES user_id=28849 Originator: NO ev(%o72,besselexpand:true) will produce what you want. We could also add this as a special case, if that's what people really want. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1855115&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-1215067 ] hgfred([1,1],[1/2],x) From: SourceForge.net - 2005-06-06 20:45:15 ```Bugs item #1215067, was opened at 2005-06-05 03:52 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1215067&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: Lisp Core Group: None Status: Open Resolution: None Priority: 5 Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: hgfred([1,1],[1/2],x) Initial Comment: I think hgfred([1,1],[1/2],x) evaluates incorrectly. Consider: The rising factorial (%i1) rf(x,n) := product(x+i,i,0,n-1)\$ The sum of the first three terms of 2F1 (%i2) f21(a,b,c,x) := sum(rf(a,i) * rf(b,i) * x^i/(i ! * rf(c,i)),i,0,2)\$ Let's taylor hgfred([1,1],[1/2],x) (%i3) taylor(hgfred([1,1],[1/2],x),x,0,2); (%o3) 1+(3*x)/4+(3*x^2)/4+... Compare with f21(1,1,1/2,x) (%i4) f21(1,1,1/2,x); (%o4) (8*x^2)/3+2*x+1 They disagree. Try different parameters -- this time they agree (%i5) taylor(hgfred([1,2],[3],x),x,0,2); (%o5) 1+(2*x)/3+x^2/2+... (%i6) f21(1,2,3,x); (%o6) x^2/2+(2*x)/3+1 This might be a bug in taylor. But I doubt that -- commercial macsyma's value for hgfred([1,1],[1/2]) differs from the one given by maxima (D5) asin(sqrt(x))*sqrt(x)/(1-x)^(3/2)+1/(1-x) (%i7) build_info(); Maxima version: 5.9.1 Maxima build date: 7:34 9/24/2004 host type: i686-pc-mingw32 lisp-implementation-type: Kyoto Common Lisp lisp-implementation-version: GCL 2.6.5 Barton ---------------------------------------------------------------------- >Comment By: Raymond Toy (rtoy) Date: 2005-06-06 16:45 Message: Logged In: YES user_id=28849 This appears to be fixed in CVS. Can you try that? hgfred([1,1],[1/2],x) returns something essentially equivalent to what commerical Macsyma returns. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1215067&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-1215067 ] hgfred([1,1],[1/2],x) From: SourceForge.net - 2005-06-13 18:50:00 ```Bugs item #1215067, was opened at 2005-06-05 02:52 Message generated for change (Comment added) made by willisbl You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1215067&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: Lisp Core Group: None >Status: Closed Resolution: None Priority: 5 Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: hgfred([1,1],[1/2],x) Initial Comment: I think hgfred([1,1],[1/2],x) evaluates incorrectly. Consider: The rising factorial (%i1) rf(x,n) := product(x+i,i,0,n-1)\$ The sum of the first three terms of 2F1 (%i2) f21(a,b,c,x) := sum(rf(a,i) * rf(b,i) * x^i/(i ! * rf(c,i)),i,0,2)\$ Let's taylor hgfred([1,1],[1/2],x) (%i3) taylor(hgfred([1,1],[1/2],x),x,0,2); (%o3) 1+(3*x)/4+(3*x^2)/4+... Compare with f21(1,1,1/2,x) (%i4) f21(1,1,1/2,x); (%o4) (8*x^2)/3+2*x+1 They disagree. Try different parameters -- this time they agree (%i5) taylor(hgfred([1,2],[3],x),x,0,2); (%o5) 1+(2*x)/3+x^2/2+... (%i6) f21(1,2,3,x); (%o6) x^2/2+(2*x)/3+1 This might be a bug in taylor. But I doubt that -- commercial macsyma's value for hgfred([1,1],[1/2]) differs from the one given by maxima (D5) asin(sqrt(x))*sqrt(x)/(1-x)^(3/2)+1/(1-x) (%i7) build_info(); Maxima version: 5.9.1 Maxima build date: 7:34 9/24/2004 host type: i686-pc-mingw32 lisp-implementation-type: Kyoto Common Lisp lisp-implementation-version: GCL 2.6.5 Barton ---------------------------------------------------------------------- >Comment By: Barton Willis (willisbl) Date: 2005-06-13 13:49 Message: Logged In: YES user_id=895922 Thanks--it is fixed in CVS (using GCL). I'll close the bug. Barton ---------------------------------------------------------------------- Comment By: Raymond Toy (rtoy) Date: 2005-06-06 15:45 Message: Logged In: YES user_id=28849 This appears to be fixed in CVS. Can you try that? hgfred([1,1],[1/2],x) returns something essentially equivalent to what commerical Macsyma returns. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1215067&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-1855115 ] hgfred([1],[2],x) From: SourceForge.net - 2007-12-21 04:12:40 ```Bugs item #1855115, was opened at 2007-12-20 13:29 Message generated for change (Comment added) made by willisbl You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1855115&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: Lisp Core Group: None >Status: Closed >Resolution: Invalid Priority: 5 Private: No Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: hgfred([1],[2],x) Initial Comment: A&S 13.6.13 tells us that 1F1(1,2,x) = 2 * exp(x/2) * sinh(x/2) / x but (%i72) hgfred([1],[2],x); (%o72) (sqrt(%pi)*bessel_i(1/2,x/2)*%e^(x/2))/sqrt(x) I think (%o72) isn't wrong, but I don't think it's what we want. ---------------------------------------------------------------------- >Comment By: Barton Willis (willisbl) Date: 2007-12-20 22:12 Message: Logged In: YES user_id=895922 Originator: YES This isn't a bug and there is a workaround. I'll close the bug. ---------------------------------------------------------------------- Comment By: Raymond Toy (rtoy) Date: 2007-12-20 18:30 Message: Logged In: YES user_id=28849 Originator: NO ev(%o72,besselexpand:true) will produce what you want. We could also add this as a special case, if that's what people really want. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1855115&group_id=4933 ```