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From: SourceForge.net <noreply@so...>  20070107 06:15:59

Bugs item #1629723, was opened at 20070106 22:15 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=1629723&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  Limit Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: bug in limit, asks sign of IND, encountered in integrator Initial Comment: quoted from the mailing list: On 12/11/06, Daniel Lakeland <dlakelan@...> wrote: >integrate(abs(sin(x)/x),x,0,inf) asks the seemingly stupid question: >Is ind positive, negative, or zero? > >the user has absolutely no idea what maxima is asking... I'm going to >assume that it has something to do with a change of variable deep >within the integrator... but it's completely opaque to me. This is definitely a bug, and should be reported. Integrate is calling limit, and the bug is actually in the limit routine: limit( abs(sin(x))/x , x , inf) => asks sign of ind IND is supposed to be used by Limit as a return value meaning that the limit set is bounded, e.g. limit(sin(x),x,inf) => ind, but obviously here it's gotten its wires crossed. I suggest you write up the limit bug with a note that definite integration encounters it.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1629723&group_id=4933 
From: SourceForge.net <noreply@so...>  20070922 14:47:38

Bugs item #1629723, was opened at 20070107 01:15 Message generated for change (Comment added) made by dgildea You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1629723&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  Limit Group: None >Status: Closed >Resolution: Fixed Priority: 5 Private: No Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: bug in limit, asks sign of IND, encountered in integrator Initial Comment: quoted from the mailing list: On 12/11/06, Daniel Lakeland <dlakelan@...> wrote: >integrate(abs(sin(x)/x),x,0,inf) asks the seemingly stupid question: >Is ind positive, negative, or zero? > >the user has absolutely no idea what maxima is asking... I'm going to >assume that it has something to do with a change of variable deep >within the integrator... but it's completely opaque to me. This is definitely a bug, and should be reported. Integrate is calling limit, and the bug is actually in the limit routine: limit( abs(sin(x))/x , x , inf) => asks sign of ind IND is supposed to be used by Limit as a return value meaning that the limit set is bounded, e.g. limit(sin(x),x,inf) => ind, but obviously here it's gotten its wires crossed. I suggest you write up the limit bug with a note that definite integration encounters it.  >Comment By: Dan Gildea (dgildea) Date: 20070922 10:47 Message: Logged In: YES user_id=1797506 Originator: NO Fixed in limit.lisp rev 1.40. (%i3) limit( abs(sin(x))/x , x , inf) ; (%o3) ind  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1629723&group_id=4933 
From: SourceForge.net <noreply@so...>  20070922 14:56:10

Bugs item #1629723, was opened at 20070107 01:15 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1629723&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  Limit Group: None >Status: Open >Resolution: None Priority: 5 Private: No Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: bug in limit, asks sign of IND, encountered in integrator Initial Comment: quoted from the mailing list: On 12/11/06, Daniel Lakeland <dlakelan@...> wrote: >integrate(abs(sin(x)/x),x,0,inf) asks the seemingly stupid question: >Is ind positive, negative, or zero? > >the user has absolutely no idea what maxima is asking... I'm going to >assume that it has something to do with a change of variable deep >within the integrator... but it's completely opaque to me. This is definitely a bug, and should be reported. Integrate is calling limit, and the bug is actually in the limit routine: limit( abs(sin(x))/x , x , inf) => asks sign of ind IND is supposed to be used by Limit as a return value meaning that the limit set is bounded, e.g. limit(sin(x),x,inf) => ind, but obviously here it's gotten its wires crossed. I suggest you write up the limit bug with a note that definite integration encounters it.  >Comment By: Raymond Toy (rtoy) Date: 20070922 10:56 Message: Logged In: YES user_id=28849 Originator: NO Why is limit(abs(sin(x))/x, x, inf) ind? Shouldn't it be zero? abs(sin(x))/x is surely bounded between 0 and 1/x. Am I missing something? Reopening.  Comment By: Dan Gildea (dgildea) Date: 20070922 10:47 Message: Logged In: YES user_id=1797506 Originator: NO Fixed in limit.lisp rev 1.40. (%i3) limit( abs(sin(x))/x , x , inf) ; (%o3) ind  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1629723&group_id=4933 
From: SourceForge.net <noreply@so...>  20070922 16:49:55

Bugs item #1629723, was opened at 20070107 01:15 Message generated for change (Comment added) made by dgildea You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1629723&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  Limit Group: None >Status: Closed >Resolution: Fixed Priority: 5 Private: No Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: bug in limit, asks sign of IND, encountered in integrator Initial Comment: quoted from the mailing list: On 12/11/06, Daniel Lakeland <dlakelan@...> wrote: >integrate(abs(sin(x)/x),x,0,inf) asks the seemingly stupid question: >Is ind positive, negative, or zero? > >the user has absolutely no idea what maxima is asking... I'm going to >assume that it has something to do with a change of variable deep >within the integrator... but it's completely opaque to me. This is definitely a bug, and should be reported. Integrate is calling limit, and the bug is actually in the limit routine: limit( abs(sin(x))/x , x , inf) => asks sign of ind IND is supposed to be used by Limit as a return value meaning that the limit set is bounded, e.g. limit(sin(x),x,inf) => ind, but obviously here it's gotten its wires crossed. I suggest you write up the limit bug with a note that definite integration encounters it.  >Comment By: Dan Gildea (dgildea) Date: 20070922 12:49 Message: Logged In: YES user_id=1797506 Originator: NO oops, sorry. in limit.lisp rev 1.41: limit(abs(sin(x))/x, x, inf) => 0 however: limit(abs(sin(x))/sin(x), x, inf) => 1 still not correct  Comment By: Raymond Toy (rtoy) Date: 20070922 10:56 Message: Logged In: YES user_id=28849 Originator: NO Why is limit(abs(sin(x))/x, x, inf) ind? Shouldn't it be zero? abs(sin(x))/x is surely bounded between 0 and 1/x. Am I missing something? Reopening.  Comment By: Dan Gildea (dgildea) Date: 20070922 10:47 Message: Logged In: YES user_id=1797506 Originator: NO Fixed in limit.lisp rev 1.40. (%i3) limit( abs(sin(x))/x , x , inf) ; (%o3) ind  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1629723&group_id=4933 