Learn how easy it is to sync an existing GitHub or Google Code repo to a SourceForge project! See Demo
Close
From: SourceForge.net <noreply@so...>  20100217 08:56:10

Bugs item #2953369, was opened at 20100217 08:56 Message generated for change (Tracker Item Submitted) made by nobody You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2953369&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: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Definite Integration of 1/(ab*cos(x)) wrong Initial Comment: Maxima 5.20.1 with wxMaxima. integrate(1/(ab*cos(x)),x,0,%pi); where a>0, 0<b<a yields 0.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2953369&group_id=4933 
From: SourceForge.net <noreply@so...>  20100226 06:45:06

Bugs item #2953369, was opened at 20100217 02:56 Message generated for change (Comment added) made by willisbl You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2953369&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: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Definite Integration of 1/(ab*cos(x)) wrong Initial Comment: Maxima 5.20.1 with wxMaxima. integrate(1/(ab*cos(x)),x,0,%pi); where a>0, 0<b<a yields 0.  >Comment By: Barton Willis (willisbl) Date: 20100226 00:45 Message: Notice how a float enters into the asksign: (%i4) integrate(1/(1a*cos(x)),x); Is a^21.0 positive or negative?neg; (%o4) (2*atan(((2*a+2)*sin(x))/(2*sqrt(1a^2)*(cos(x)+1))))/sqrt(1a^2)  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2953369&group_id=4933 
From: SourceForge.net <noreply@so...>  20100323 12:03:51

Bugs item #2953369, was opened at 20100217 03:56 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2953369&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: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Definite Integration of 1/(ab*cos(x)) wrong Initial Comment: Maxima 5.20.1 with wxMaxima. integrate(1/(ab*cos(x)),x,0,%pi); where a>0, 0<b<a yields 0.  >Comment By: Raymond Toy (rtoy) Date: 20100323 08:03 Message: The incorrect result comes from polelist failing to identify the locations of the poles. Since the integrand is even, we can integrate from %pi to %pi (or 0 to 2*%pi) and take half of the result. This integral is converted to the contour integral of 2/(b*yy^22*a*y+b) around the unit circle. This is evaluated by residues. We want to find the poles inside the unit circle and polelist is supposed to do that. The poles are correctly determined, but unfortunately for these poles, polelist cannot find the one pole that is in the circle. Therefore the function res thinks there are no poles in the unit circle and returns 0. When a and b are numbers, polelist does a better job and normally determines the pole that is within the unit circle. Perhaps the function that determines whether the pole is in the unit circle needs to be enhanced?  Comment By: Barton Willis (willisbl) Date: 20100226 01:45 Message: Notice how a float enters into the asksign: (%i4) integrate(1/(1a*cos(x)),x); Is a^21.0 positive or negative?neg; (%o4) (2*atan(((2*a+2)*sin(x))/(2*sqrt(1a^2)*(cos(x)+1))))/sqrt(1a^2)  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2953369&group_id=4933 
From: SourceForge.net <noreply@so...>  20100324 09:32:16

Bugs item #2953369, was opened at 20100217 03:56 Message generated for change (Comment added) made by dgildea You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2953369&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: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Definite Integration of 1/(ab*cos(x)) wrong Initial Comment: Maxima 5.20.1 with wxMaxima. integrate(1/(ab*cos(x)),x,0,%pi); where a>0, 0<b<a yields 0.  >Comment By: Dan Gildea (dgildea) Date: 20100324 05:32 Message: possible solution: (defun unitcir (grand var) (numden grand) (let ((result (princip (res nn* dn* #'(lambda (pt) (eq (let ((limitp nil)) ($asksign (m+ 1 (cabs pt)))) '$neg)) #'(lambda (pt) (alike1 1 (cabs pt))))))) (cond (result (m* '$%pi result)) (t nil))))  Comment By: Raymond Toy (rtoy) Date: 20100323 08:03 Message: The incorrect result comes from polelist failing to identify the locations of the poles. Since the integrand is even, we can integrate from %pi to %pi (or 0 to 2*%pi) and take half of the result. This integral is converted to the contour integral of 2/(b*yy^22*a*y+b) around the unit circle. This is evaluated by residues. We want to find the poles inside the unit circle and polelist is supposed to do that. The poles are correctly determined, but unfortunately for these poles, polelist cannot find the one pole that is in the circle. Therefore the function res thinks there are no poles in the unit circle and returns 0. When a and b are numbers, polelist does a better job and normally determines the pole that is within the unit circle. Perhaps the function that determines whether the pole is in the unit circle needs to be enhanced?  Comment By: Barton Willis (willisbl) Date: 20100226 01:45 Message: Notice how a float enters into the asksign: (%i4) integrate(1/(1a*cos(x)),x); Is a^21.0 positive or negative?neg; (%o4) (2*atan(((2*a+2)*sin(x))/(2*sqrt(1a^2)*(cos(x)+1))))/sqrt(1a^2)  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2953369&group_id=4933 
From: SourceForge.net <noreply@so...>  20100325 02:05:38

Bugs item #2953369, was opened at 20100217 03:56 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2953369&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: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Definite Integration of 1/(ab*cos(x)) wrong Initial Comment: Maxima 5.20.1 with wxMaxima. integrate(1/(ab*cos(x)),x,0,%pi); where a>0, 0<b<a yields 0.  >Comment By: Raymond Toy (rtoy) Date: 20100324 22:05 Message: Yes, that works nicely. Need to make the second lambda also call asksign. And since the question is the same, it's nice to cache the answer from the first lambda.  Comment By: Dan Gildea (dgildea) Date: 20100324 05:32 Message: possible solution: (defun unitcir (grand var) (numden grand) (let ((result (princip (res nn* dn* #'(lambda (pt) (eq (let ((limitp nil)) ($asksign (m+ 1 (cabs pt)))) '$neg)) #'(lambda (pt) (alike1 1 (cabs pt))))))) (cond (result (m* '$%pi result)) (t nil))))  Comment By: Raymond Toy (rtoy) Date: 20100323 08:03 Message: The incorrect result comes from polelist failing to identify the locations of the poles. Since the integrand is even, we can integrate from %pi to %pi (or 0 to 2*%pi) and take half of the result. This integral is converted to the contour integral of 2/(b*yy^22*a*y+b) around the unit circle. This is evaluated by residues. We want to find the poles inside the unit circle and polelist is supposed to do that. The poles are correctly determined, but unfortunately for these poles, polelist cannot find the one pole that is in the circle. Therefore the function res thinks there are no poles in the unit circle and returns 0. When a and b are numbers, polelist does a better job and normally determines the pole that is within the unit circle. Perhaps the function that determines whether the pole is in the unit circle needs to be enhanced?  Comment By: Barton Willis (willisbl) Date: 20100226 01:45 Message: Notice how a float enters into the asksign: (%i4) integrate(1/(1a*cos(x)),x); Is a^21.0 positive or negative?neg; (%o4) (2*atan(((2*a+2)*sin(x))/(2*sqrt(1a^2)*(cos(x)+1))))/sqrt(1a^2)  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2953369&group_id=4933 
From: SourceForge.net <noreply@so...>  20100325 11:33:47

Bugs item #2953369, was opened at 20100217 03:56 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2953369&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: Fixed Priority: 5 Private: No Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Definite Integration of 1/(ab*cos(x)) wrong Initial Comment: Maxima 5.20.1 with wxMaxima. integrate(1/(ab*cos(x)),x,0,%pi); where a>0, 0<b<a yields 0.  >Comment By: Raymond Toy (rtoy) Date: 20100325 07:33 Message: dgildea's basic solution checked in. Closing bug.  Comment By: Raymond Toy (rtoy) Date: 20100324 22:05 Message: Yes, that works nicely. Need to make the second lambda also call asksign. And since the question is the same, it's nice to cache the answer from the first lambda.  Comment By: Dan Gildea (dgildea) Date: 20100324 05:32 Message: possible solution: (defun unitcir (grand var) (numden grand) (let ((result (princip (res nn* dn* #'(lambda (pt) (eq (let ((limitp nil)) ($asksign (m+ 1 (cabs pt)))) '$neg)) #'(lambda (pt) (alike1 1 (cabs pt))))))) (cond (result (m* '$%pi result)) (t nil))))  Comment By: Raymond Toy (rtoy) Date: 20100323 08:03 Message: The incorrect result comes from polelist failing to identify the locations of the poles. Since the integrand is even, we can integrate from %pi to %pi (or 0 to 2*%pi) and take half of the result. This integral is converted to the contour integral of 2/(b*yy^22*a*y+b) around the unit circle. This is evaluated by residues. We want to find the poles inside the unit circle and polelist is supposed to do that. The poles are correctly determined, but unfortunately for these poles, polelist cannot find the one pole that is in the circle. Therefore the function res thinks there are no poles in the unit circle and returns 0. When a and b are numbers, polelist does a better job and normally determines the pole that is within the unit circle. Perhaps the function that determines whether the pole is in the unit circle needs to be enhanced?  Comment By: Barton Willis (willisbl) Date: 20100226 01:45 Message: Notice how a float enters into the asksign: (%i4) integrate(1/(1a*cos(x)),x); Is a^21.0 positive or negative?neg; (%o4) (2*atan(((2*a+2)*sin(x))/(2*sqrt(1a^2)*(cos(x)+1))))/sqrt(1a^2)  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2953369&group_id=4933 