From: SourceForge.net <no...@so...> - 2009-05-13 02:00:52
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Bugs item #2790984, was opened at 2009-05-12 20:55 Message generated for change (Tracker Item Submitted) made by caprilo You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2790984&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 - Integration Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: caprilo (caprilo) Assigned to: Nobody/Anonymous (nobody) Summary: problem with sqrt(a-bx^2) calculus Initial Comment: The function integrate(sqrt(a-bx^2), x); returns sqrt(a-bx^2)*x which is obviously wrong. Worse is that, the differentiation of the wrong integral, diff(sqrt(a-bx^2)*x, x); returns the integrand!: sqrt(a-bx^2) ------------------------------------------------------------- Maxima version: 5.13.0 Maxima build date: 9:20 12/12/2007 host type: i686-pc-linux-gnu lisp-implementation-type: GNU Common Lisp (GCL) lisp-implementation-version: GCL 2.6.8 ------------------------------------------------------------- ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2790984&group_id=4933 |
From: SourceForge.net <no...@so...> - 2009-05-13 03:48:41
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Bugs item #2790984, was opened at 2009-05-12 21:55 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2790984&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 - Integration Group: None >Status: Pending >Resolution: Invalid Priority: 5 Private: No Submitted By: caprilo (caprilo) Assigned to: Nobody/Anonymous (nobody) Summary: problem with sqrt(a-bx^2) calculus Initial Comment: The function integrate(sqrt(a-bx^2), x); returns sqrt(a-bx^2)*x which is obviously wrong. Worse is that, the differentiation of the wrong integral, diff(sqrt(a-bx^2)*x, x); returns the integrand!: sqrt(a-bx^2) ------------------------------------------------------------- Maxima version: 5.13.0 Maxima build date: 9:20 12/12/2007 host type: i686-pc-linux-gnu lisp-implementation-type: GNU Common Lisp (GCL) lisp-implementation-version: GCL 2.6.8 ------------------------------------------------------------- ---------------------------------------------------------------------- >Comment By: Raymond Toy (rtoy) Date: 2009-05-12 23:48 Message: bx^2 is not the same as b*x^2, so you've basically integrated y wrt to x, which is y*x. Same with your differentiation. Marking this as pending/invalid. If this analysis is incorrect, please comment. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2790984&group_id=4933 |
From: SourceForge.net <no...@so...> - 2009-05-13 11:38:55
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Bugs item #2790984, was opened at 2009-05-13 01:55 Message generated for change (Comment added) made by nobody You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2790984&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 - Integration Group: None Status: Pending Resolution: Invalid Priority: 5 Private: No Submitted By: caprilo (caprilo) Assigned to: Nobody/Anonymous (nobody) Summary: problem with sqrt(a-bx^2) calculus Initial Comment: The function integrate(sqrt(a-bx^2), x); returns sqrt(a-bx^2)*x which is obviously wrong. Worse is that, the differentiation of the wrong integral, diff(sqrt(a-bx^2)*x, x); returns the integrand!: sqrt(a-bx^2) ------------------------------------------------------------- Maxima version: 5.13.0 Maxima build date: 9:20 12/12/2007 host type: i686-pc-linux-gnu lisp-implementation-type: GNU Common Lisp (GCL) lisp-implementation-version: GCL 2.6.8 ------------------------------------------------------------- ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2009-05-13 11:38 Message: Input notation is different from output in mathematical notation as provided by Maxima. rtoy did give the right answer and the worse was for the better, namely that Maxima returned the function when differentiating the integral of the function. ---------------------------------------------------------------------- Comment By: Raymond Toy (rtoy) Date: 2009-05-13 03:48 Message: bx^2 is not the same as b*x^2, so you've basically integrated y wrt to x, which is y*x. Same with your differentiation. Marking this as pending/invalid. If this analysis is incorrect, please comment. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2790984&group_id=4933 |
From: SourceForge.net <no...@so...> - 2009-05-28 02:20:22
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Bugs item #2790984, was opened at 2009-05-13 01:55 Message generated for change (Comment added) made by sf-robot You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2790984&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 - Integration Group: None >Status: Closed Resolution: Invalid Priority: 5 Private: No Submitted By: caprilo (caprilo) Assigned to: Nobody/Anonymous (nobody) Summary: problem with sqrt(a-bx^2) calculus Initial Comment: The function integrate(sqrt(a-bx^2), x); returns sqrt(a-bx^2)*x which is obviously wrong. Worse is that, the differentiation of the wrong integral, diff(sqrt(a-bx^2)*x, x); returns the integrand!: sqrt(a-bx^2) ------------------------------------------------------------- Maxima version: 5.13.0 Maxima build date: 9:20 12/12/2007 host type: i686-pc-linux-gnu lisp-implementation-type: GNU Common Lisp (GCL) lisp-implementation-version: GCL 2.6.8 ------------------------------------------------------------- ---------------------------------------------------------------------- >Comment By: SourceForge Robot (sf-robot) Date: 2009-05-28 02:20 Message: This Tracker item was closed automatically by the system. It was previously set to a Pending status, and the original submitter did not respond within 14 days (the time period specified by the administrator of this Tracker). ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2009-05-13 11:38 Message: Input notation is different from output in mathematical notation as provided by Maxima. rtoy did give the right answer and the worse was for the better, namely that Maxima returned the function when differentiating the integral of the function. ---------------------------------------------------------------------- Comment By: Raymond Toy (rtoy) Date: 2009-05-13 03:48 Message: bx^2 is not the same as b*x^2, so you've basically integrated y wrt to x, which is y*x. Same with your differentiation. Marking this as pending/invalid. If this analysis is incorrect, please comment. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2790984&group_id=4933 |