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From: SourceForge.net <noreply@so...>  20090522 18:46:35

Bugs item #2795534, was opened at 20090522 20:46 Message generated for change (Tracker Item Submitted) made by crategus You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2795534&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: Dieter Kaiser (crategus) Assigned to: Nobody/Anonymous (nobody) Summary: integrate(expintegral_ei(x),x,0,1) gives result with TRUE Initial Comment: When we do the above integral we get an expression with the symbol TRUE in it: (%i14) integrate(expintegral_ei(x),x,0,1); (%o14) expintegral_ei(1)true%e The same for expintegral_ci and expintegral_chi: (%i16) integrate(expintegral_ci(x),x,0,1); (%o16) sin(1)+expintegral_ci(1)true (%i18) integrate(expintegral_chi(x),x,0,1); (%o18) sinh(1)+expintegral_chi(1)true Dieter Kaiser  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2795534&group_id=4933 
From: SourceForge.net <noreply@so...>  20090604 20:20:56

Bugs item #2795534, was opened at 20090522 20:46 Message generated for change (Comment added) made by crategus You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2795534&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: Dieter Kaiser (crategus) Assigned to: Nobody/Anonymous (nobody) Summary: integrate(expintegral_ei(x),x,0,1) gives result with TRUE Initial Comment: When we do the above integral we get an expression with the symbol TRUE in it: (%i14) integrate(expintegral_ei(x),x,0,1); (%o14) expintegral_ei(1)true%e The same for expintegral_ci and expintegral_chi: (%i16) integrate(expintegral_ci(x),x,0,1); (%o16) sin(1)+expintegral_ci(1)true (%i18) integrate(expintegral_chi(x),x,0,1); (%o18) sinh(1)+expintegral_chi(1)true Dieter Kaiser  >Comment By: Dieter Kaiser (crategus) Date: 20090604 22:20 Message: Maxima should be able to solve integrals of the type given in this bug report. Other integrals like integrate(expintegral_ei(x),x,1/2,1) work well and give correct results. There are two problems. 1. A bug in defint Because of a bug in defint, we get the symbol true in the result. The reason is a missing check of the return value of noerrsub against T in the routine easysubs. This bug is easy to cure. 2. A bug in limit The limit of x*expintegral_ei(x) > 0 has to be calculated. The limit of expintegral_ei(x) > 0 is known by Maxima. Therefore Maxima should be able do get the correct answer, but Maxima tries to calculated the function at the value 0. This gives an error and the calculation stops. I am looking into the code to find a solution to the second problem too. Dieter Kaiser  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2795534&group_id=4933 
From: SourceForge.net <noreply@so...>  20090605 15:50:11

Bugs item #2795534, was opened at 20090522 20:46 Message generated for change (Comment added) made by crategus You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2795534&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: Dieter Kaiser (crategus) Assigned to: Nobody/Anonymous (nobody) Summary: integrate(expintegral_ei(x),x,0,1) gives result with TRUE Initial Comment: When we do the above integral we get an expression with the symbol TRUE in it: (%i14) integrate(expintegral_ei(x),x,0,1); (%o14) expintegral_ei(1)true%e The same for expintegral_ci and expintegral_chi: (%i16) integrate(expintegral_ci(x),x,0,1); (%o16) sin(1)+expintegral_ci(1)true (%i18) integrate(expintegral_chi(x),x,0,1); (%o18) sinh(1)+expintegral_chi(1)true Dieter Kaiser  >Comment By: Dieter Kaiser (crategus) Date: 20090605 17:50 Message: A check to the routine easysubs in defint.lisp has been added. We no longer get a result with the symbol T in it. But the integral does not work, because of a bug in limit. (%i1) integrate(expintegral_ei(x),x,0,1); expintegral_ei: expintegral_ei(0) is undefined.  an error. To debug this try debugmode(true); Closing this bug report as fixed, because the initial problem in defint is solved. I will open a new bug report for the problem in limit. Dieter Kaiser  Comment By: Dieter Kaiser (crategus) Date: 20090604 22:20 Message: Maxima should be able to solve integrals of the type given in this bug report. Other integrals like integrate(expintegral_ei(x),x,1/2,1) work well and give correct results. There are two problems. 1. A bug in defint Because of a bug in defint, we get the symbol true in the result. The reason is a missing check of the return value of noerrsub against T in the routine easysubs. This bug is easy to cure. 2. A bug in limit The limit of x*expintegral_ei(x) > 0 has to be calculated. The limit of expintegral_ei(x) > 0 is known by Maxima. Therefore Maxima should be able do get the correct answer, but Maxima tries to calculated the function at the value 0. This gives an error and the calculation stops. I am looking into the code to find a solution to the second problem too. Dieter Kaiser  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2795534&group_id=4933 
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