From: SourceForge.net <no...@so...> - 2007-09-18 20:00:13
|
Bugs item #1797296, was opened at 2007-09-18 13:00 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=1797296&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: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Crazy results when doing limit of 'diff Initial Comment: Maxima version: 5.13.0Maxima build date: 15:45 9/16/2007host type: i586-pc-linux-gnulisp-implementation-type: CLISPlisp-implementation-version: 2.41 (2006-10-13) (built 3380066971) (memory 3398964343) Maxima returns crazy results when evaluating the limit of an unevaluated derivative: Examples: limit('diff((x+1)/(x^2-1),x),x,1); limit('diff((x+1),x),x,1); limit('diff((x+n),x),x,1); Not only is the "with respect to" variable in the demoninator of the result wrong, i.e., d/d(x+1), but the limiting value of the variable is wrong. The limit was supposed to as x -> 1, but the output shows the limit as x->0 --- reporter's email: joe.vender AT owensboro.net ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&group_id=4933 |
From: SourceForge.net <no...@so...> - 2007-09-18 20:45:35
|
Bugs item #1797296, was opened at 2007-09-18 13:00 Message generated for change (Comment added) made by nobody You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&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: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Crazy results when doing limit of 'diff Initial Comment: Maxima version: 5.13.0Maxima build date: 15:45 9/16/2007host type: i586-pc-linux-gnulisp-implementation-type: CLISPlisp-implementation-version: 2.41 (2006-10-13) (built 3380066971) (memory 3398964343) Maxima returns crazy results when evaluating the limit of an unevaluated derivative: Examples: limit('diff((x+1)/(x^2-1),x),x,1); limit('diff((x+1),x),x,1); limit('diff((x+n),x),x,1); Not only is the "with respect to" variable in the demoninator of the result wrong, i.e., d/d(x+1), but the limiting value of the variable is wrong. The limit was supposed to as x -> 1, but the output shows the limit as x->0 --- reporter's email: joe.vender AT owensboro.net ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2007-09-18 13:45 Message: Logged In: NO also; limit(('diff(x^n),x),x,1); returns 1. Notice the mismatch of the parentheses. The problem lies in that adding ",x" after 'diff(x^n) and putting parentheses around the whole expression returns whatever is put after the comma instead of (del(x^n),x). Ex. 'diff(x^n) returns del(x^n) ('diff(x^n),x) returns x ('diff(x^n),abc) returns abc which is then evaluated by the limit function. It appears that when entering something like (f(x),f(y)) maxima always outputs f(y) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&group_id=4933 |
From: SourceForge.net <no...@so...> - 2007-09-20 17:34:52
|
Bugs item #1797296, was opened at 2007-09-18 16:00 Message generated for change (Comment added) made by macrakis You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&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: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Crazy results when doing limit of 'diff Initial Comment: Maxima version: 5.13.0Maxima build date: 15:45 9/16/2007host type: i586-pc-linux-gnulisp-implementation-type: CLISPlisp-implementation-version: 2.41 (2006-10-13) (built 3380066971) (memory 3398964343) Maxima returns crazy results when evaluating the limit of an unevaluated derivative: Examples: limit('diff((x+1)/(x^2-1),x),x,1); limit('diff((x+1),x),x,1); limit('diff((x+n),x),x,1); Not only is the "with respect to" variable in the demoninator of the result wrong, i.e., d/d(x+1), but the limiting value of the variable is wrong. The limit was supposed to as x -> 1, but the output shows the limit as x->0 --- reporter's email: joe.vender AT owensboro.net ---------------------------------------------------------------------- >Comment By: Stavros Macrakis (macrakis) Date: 2007-09-20 13:34 Message: Logged In: YES user_id=588346 Originator: NO The original bug is valid. A simple case: limit('diff(y,x),x,1) => 'limit('diff(y,x+1,1),x,0) The followup comment is confused. The syntax (..., ..., ...) in Maxima evaluates each of the elements of the list and returns the last value. This is the correct behavior. ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2007-09-18 16:45 Message: Logged In: NO also; limit(('diff(x^n),x),x,1); returns 1. Notice the mismatch of the parentheses. The problem lies in that adding ",x" after 'diff(x^n) and putting parentheses around the whole expression returns whatever is put after the comma instead of (del(x^n),x). Ex. 'diff(x^n) returns del(x^n) ('diff(x^n),x) returns x ('diff(x^n),abc) returns abc which is then evaluated by the limit function. It appears that when entering something like (f(x),f(y)) maxima always outputs f(y) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&group_id=4933 |
From: SourceForge.net <no...@so...> - 2007-09-23 16:41:57
|
Bugs item #1797296, was opened at 2007-09-18 14:00 Message generated for change (Settings changed) made by robert_dodier You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&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: Crazy results when doing limit of 'diff Initial Comment: Maxima version: 5.13.0Maxima build date: 15:45 9/16/2007host type: i586-pc-linux-gnulisp-implementation-type: CLISPlisp-implementation-version: 2.41 (2006-10-13) (built 3380066971) (memory 3398964343) Maxima returns crazy results when evaluating the limit of an unevaluated derivative: Examples: limit('diff((x+1)/(x^2-1),x),x,1); limit('diff((x+1),x),x,1); limit('diff((x+n),x),x,1); Not only is the "with respect to" variable in the demoninator of the result wrong, i.e., d/d(x+1), but the limiting value of the variable is wrong. The limit was supposed to as x -> 1, but the output shows the limit as x->0 --- reporter's email: joe.vender AT owensboro.net ---------------------------------------------------------------------- Comment By: Stavros Macrakis (macrakis) Date: 2007-09-20 11:34 Message: Logged In: YES user_id=588346 Originator: NO The original bug is valid. A simple case: limit('diff(y,x),x,1) => 'limit('diff(y,x+1,1),x,0) The followup comment is confused. The syntax (..., ..., ...) in Maxima evaluates each of the elements of the list and returns the last value. This is the correct behavior. ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2007-09-18 14:45 Message: Logged In: NO also; limit(('diff(x^n),x),x,1); returns 1. Notice the mismatch of the parentheses. The problem lies in that adding ",x" after 'diff(x^n) and putting parentheses around the whole expression returns whatever is put after the comma instead of (del(x^n),x). Ex. 'diff(x^n) returns del(x^n) ('diff(x^n),x) returns x ('diff(x^n),abc) returns abc which is then evaluated by the limit function. It appears that when entering something like (f(x),f(y)) maxima always outputs f(y) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&group_id=4933 |
From: SourceForge.net <no...@so...> - 2007-10-08 02:49:31
|
Bugs item #1797296, was opened at 2007-09-18 13:00 Message generated for change (Comment added) made by nobody You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&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: Crazy results when doing limit of 'diff Initial Comment: Maxima version: 5.13.0Maxima build date: 15:45 9/16/2007host type: i586-pc-linux-gnulisp-implementation-type: CLISPlisp-implementation-version: 2.41 (2006-10-13) (built 3380066971) (memory 3398964343) Maxima returns crazy results when evaluating the limit of an unevaluated derivative: Examples: limit('diff((x+1)/(x^2-1),x),x,1); limit('diff((x+1),x),x,1); limit('diff((x+n),x),x,1); Not only is the "with respect to" variable in the demoninator of the result wrong, i.e., d/d(x+1), but the limiting value of the variable is wrong. The limit was supposed to as x -> 1, but the output shows the limit as x->0 --- reporter's email: joe.vender AT owensboro.net ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2007-10-07 19:49 Message: Logged In: NO limit(diff((x+1)/(x^2-1),x),x,1); works fine . and also the others: limit(diff((x+1),x),x,1); limit(diff((x+n),x),x,1); ---------------------------------------------------------------------- Comment By: Stavros Macrakis (macrakis) Date: 2007-09-20 10:34 Message: Logged In: YES user_id=588346 Originator: NO The original bug is valid. A simple case: limit('diff(y,x),x,1) => 'limit('diff(y,x+1,1),x,0) The followup comment is confused. The syntax (..., ..., ...) in Maxima evaluates each of the elements of the list and returns the last value. This is the correct behavior. ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2007-09-18 13:45 Message: Logged In: NO also; limit(('diff(x^n),x),x,1); returns 1. Notice the mismatch of the parentheses. The problem lies in that adding ",x" after 'diff(x^n) and putting parentheses around the whole expression returns whatever is put after the comma instead of (del(x^n),x). Ex. 'diff(x^n) returns del(x^n) ('diff(x^n),x) returns x ('diff(x^n),abc) returns abc which is then evaluated by the limit function. It appears that when entering something like (f(x),f(y)) maxima always outputs f(y) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&group_id=4933 |
From: SourceForge.net <no...@so...> - 2007-10-08 14:03:53
|
Bugs item #1797296, was opened at 2007-09-18 16:00 Message generated for change (Comment added) made by macrakis You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&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: Crazy results when doing limit of 'diff Initial Comment: Maxima version: 5.13.0Maxima build date: 15:45 9/16/2007host type: i586-pc-linux-gnulisp-implementation-type: CLISPlisp-implementation-version: 2.41 (2006-10-13) (built 3380066971) (memory 3398964343) Maxima returns crazy results when evaluating the limit of an unevaluated derivative: Examples: limit('diff((x+1)/(x^2-1),x),x,1); limit('diff((x+1),x),x,1); limit('diff((x+n),x),x,1); Not only is the "with respect to" variable in the demoninator of the result wrong, i.e., d/d(x+1), but the limiting value of the variable is wrong. The limit was supposed to as x -> 1, but the output shows the limit as x->0 --- reporter's email: joe.vender AT owensboro.net ---------------------------------------------------------------------- >Comment By: Stavros Macrakis (macrakis) Date: 2007-10-08 10:03 Message: Logged In: YES user_id=588346 Originator: NO Dear "nobody" (2007-10-07 22:49), the quotation mark (') in the original bug report is critical. There is no problem with limit(diff((x+1),x),x,1); there *is* a problem with limit('diff((x+1),x),x,1). ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2007-10-07 22:49 Message: Logged In: NO limit(diff((x+1)/(x^2-1),x),x,1); works fine . and also the others: limit(diff((x+1),x),x,1); limit(diff((x+n),x),x,1); ---------------------------------------------------------------------- Comment By: Stavros Macrakis (macrakis) Date: 2007-09-20 13:34 Message: Logged In: YES user_id=588346 Originator: NO The original bug is valid. A simple case: limit('diff(y,x),x,1) => 'limit('diff(y,x+1,1),x,0) The followup comment is confused. The syntax (..., ..., ...) in Maxima evaluates each of the elements of the list and returns the last value. This is the correct behavior. ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2007-09-18 16:45 Message: Logged In: NO also; limit(('diff(x^n),x),x,1); returns 1. Notice the mismatch of the parentheses. The problem lies in that adding ",x" after 'diff(x^n) and putting parentheses around the whole expression returns whatever is put after the comma instead of (del(x^n),x). Ex. 'diff(x^n) returns del(x^n) ('diff(x^n),x) returns x ('diff(x^n),abc) returns abc which is then evaluated by the limit function. It appears that when entering something like (f(x),f(y)) maxima always outputs f(y) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&group_id=4933 |
From: SourceForge.net <no...@so...> - 2009-08-29 20:15:25
|
Bugs item #1797296, was opened at 2007-09-18 22:00 Message generated for change (Comment added) made by crategus You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&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: Crazy results when doing limit of 'diff Initial Comment: Maxima version: 5.13.0Maxima build date: 15:45 9/16/2007host type: i586-pc-linux-gnulisp-implementation-type: CLISPlisp-implementation-version: 2.41 (2006-10-13) (built 3380066971) (memory 3398964343) Maxima returns crazy results when evaluating the limit of an unevaluated derivative: Examples: limit('diff((x+1)/(x^2-1),x),x,1); limit('diff((x+1),x),x,1); limit('diff((x+n),x),x,1); Not only is the "with respect to" variable in the demoninator of the result wrong, i.e., d/d(x+1), but the limiting value of the variable is wrong. The limit was supposed to as x -> 1, but the output shows the limit as x->0 --- reporter's email: joe.vender AT owensboro.net ---------------------------------------------------------------------- >Comment By: Dieter Kaiser (crategus) Date: 2009-08-29 22:15 Message: Limit does not try to simplify noun forms of derivatives, but replaces the noun forms by a gensym. This is done in $limit with a call to hide in the following line of code: (setq exp (resimplify (factosimp (tansc (lfibtophi (limitsimp ($expand (hide exp) 1 0) var)))))) I think the problem is, that hide is called to late. At this point the limit values have already been transformed. This is a piece of the corrected code: ;; Hide expressions with limit, derivative, integrate, sum ;; before any transformations of the limit values (setq exp (hide exp)) ;; Transform the limit value. (unless (infinityp val) (unless (zerop2 val) (setq exp (subin (m+ var val) exp))) (setq val (cond ((eq dr '$plus) '$zeroa) ((eq dr '$minus) '$zerob) (t 0))) (setq origval 0)) (setq exp (resimplify (factosimp (tansc (lfibtophi (limitsimp ($expand exp 1 0) var)))))) These are the results for the reported examples: (%i11) limit('diff((x+1)/(x^2-1),x),x,1); (%o11) 'limit('diff((x+1)/(x^2-1),x,1),x,1) (%i12) limit('diff((x+1),x),x,1); (%o12) 'limit('diff(x+1,x,1),x,1) (%i13) limit('diff((x+n),x),x,1); (%o13) 'limit('diff(x+n,x,1),x,1) This change solves similar problems with the limit of 'integrate too. Dieter Kaiser ---------------------------------------------------------------------- Comment By: Stavros Macrakis (macrakis) Date: 2007-10-08 16:03 Message: Logged In: YES user_id=588346 Originator: NO Dear "nobody" (2007-10-07 22:49), the quotation mark (') in the original bug report is critical. There is no problem with limit(diff((x+1),x),x,1); there *is* a problem with limit('diff((x+1),x),x,1). ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2007-10-08 04:49 Message: Logged In: NO limit(diff((x+1)/(x^2-1),x),x,1); works fine . and also the others: limit(diff((x+1),x),x,1); limit(diff((x+n),x),x,1); ---------------------------------------------------------------------- Comment By: Stavros Macrakis (macrakis) Date: 2007-09-20 19:34 Message: Logged In: YES user_id=588346 Originator: NO The original bug is valid. A simple case: limit('diff(y,x),x,1) => 'limit('diff(y,x+1,1),x,0) The followup comment is confused. The syntax (..., ..., ...) in Maxima evaluates each of the elements of the list and returns the last value. This is the correct behavior. ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2007-09-18 22:45 Message: Logged In: NO also; limit(('diff(x^n),x),x,1); returns 1. Notice the mismatch of the parentheses. The problem lies in that adding ",x" after 'diff(x^n) and putting parentheses around the whole expression returns whatever is put after the comma instead of (del(x^n),x). Ex. 'diff(x^n) returns del(x^n) ('diff(x^n),x) returns x ('diff(x^n),abc) returns abc which is then evaluated by the limit function. It appears that when entering something like (f(x),f(y)) maxima always outputs f(y) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&group_id=4933 |
From: SourceForge.net <no...@so...> - 2009-09-04 12:43:09
|
Bugs item #1797296, was opened at 2007-09-18 22:00 Message generated for change (Settings changed) made by crategus You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&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: Crazy results when doing limit of 'diff Initial Comment: Maxima version: 5.13.0Maxima build date: 15:45 9/16/2007host type: i586-pc-linux-gnulisp-implementation-type: CLISPlisp-implementation-version: 2.41 (2006-10-13) (built 3380066971) (memory 3398964343) Maxima returns crazy results when evaluating the limit of an unevaluated derivative: Examples: limit('diff((x+1)/(x^2-1),x),x,1); limit('diff((x+1),x),x,1); limit('diff((x+n),x),x,1); Not only is the "with respect to" variable in the demoninator of the result wrong, i.e., d/d(x+1), but the limiting value of the variable is wrong. The limit was supposed to as x -> 1, but the output shows the limit as x->0 --- reporter's email: joe.vender AT owensboro.net ---------------------------------------------------------------------- >Comment By: Dieter Kaiser (crategus) Date: 2009-09-04 14:41 Message: Applied suggested fix in limit.lisp revision 1.87. Closing this bug report as fixed. Dieter Kaiser ---------------------------------------------------------------------- Comment By: Dieter Kaiser (crategus) Date: 2009-08-29 22:15 Message: Limit does not try to simplify noun forms of derivatives, but replaces the noun forms by a gensym. This is done in $limit with a call to hide in the following line of code: (setq exp (resimplify (factosimp (tansc (lfibtophi (limitsimp ($expand (hide exp) 1 0) var)))))) I think the problem is, that hide is called to late. At this point the limit values have already been transformed. This is a piece of the corrected code: ;; Hide expressions with limit, derivative, integrate, sum ;; before any transformations of the limit values (setq exp (hide exp)) ;; Transform the limit value. (unless (infinityp val) (unless (zerop2 val) (setq exp (subin (m+ var val) exp))) (setq val (cond ((eq dr '$plus) '$zeroa) ((eq dr '$minus) '$zerob) (t 0))) (setq origval 0)) (setq exp (resimplify (factosimp (tansc (lfibtophi (limitsimp ($expand exp 1 0) var)))))) These are the results for the reported examples: (%i11) limit('diff((x+1)/(x^2-1),x),x,1); (%o11) 'limit('diff((x+1)/(x^2-1),x,1),x,1) (%i12) limit('diff((x+1),x),x,1); (%o12) 'limit('diff(x+1,x,1),x,1) (%i13) limit('diff((x+n),x),x,1); (%o13) 'limit('diff(x+n,x,1),x,1) This change solves similar problems with the limit of 'integrate too. Dieter Kaiser ---------------------------------------------------------------------- Comment By: Stavros Macrakis (macrakis) Date: 2007-10-08 16:03 Message: Logged In: YES user_id=588346 Originator: NO Dear "nobody" (2007-10-07 22:49), the quotation mark (') in the original bug report is critical. There is no problem with limit(diff((x+1),x),x,1); there *is* a problem with limit('diff((x+1),x),x,1). ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2007-10-08 04:49 Message: Logged In: NO limit(diff((x+1)/(x^2-1),x),x,1); works fine . and also the others: limit(diff((x+1),x),x,1); limit(diff((x+n),x),x,1); ---------------------------------------------------------------------- Comment By: Stavros Macrakis (macrakis) Date: 2007-09-20 19:34 Message: Logged In: YES user_id=588346 Originator: NO The original bug is valid. A simple case: limit('diff(y,x),x,1) => 'limit('diff(y,x+1,1),x,0) The followup comment is confused. The syntax (..., ..., ...) in Maxima evaluates each of the elements of the list and returns the last value. This is the correct behavior. ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2007-09-18 22:45 Message: Logged In: NO also; limit(('diff(x^n),x),x,1); returns 1. Notice the mismatch of the parentheses. The problem lies in that adding ",x" after 'diff(x^n) and putting parentheses around the whole expression returns whatever is put after the comma instead of (del(x^n),x). Ex. 'diff(x^n) returns del(x^n) ('diff(x^n),x) returns x ('diff(x^n),abc) returns abc which is then evaluated by the limit function. It appears that when entering something like (f(x),f(y)) maxima always outputs f(y) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1797296&group_id=4933 |