## maxima-bugs

 [Maxima-bugs] [ maxima-Bugs-1789213 ] ic1 for solution containing indefinite integral From: SourceForge.net - 2007-09-06 08:48:30 ```Bugs item #1789213, was opened at 2007-09-06 01:48 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=1789213&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: ic1 for solution containing indefinite integral Initial Comment: It seems that ic1(s, x, y) fails to produce a meaningful result when s involves an indefinite integral. Example: (%i2) sol: ode2(kappa(p) = -'diff(V, p) / V, V, p); / [ - I kappa(p) dp ] / (%o2) V = %c %e (%i3) ic1(sol, p = p0, V = V0); / / [ [ I kappa(p0) dp0 - I kappa(p) dp ] ] / / (%o3) V = %e V0 (%i4) ic1(sol, V = V0, p = p0); / / [ [ I kappa(p0) dp0 - I kappa(p) dp ] ] / / (%o4) V = %e V0 As the two integrals in %o3 and %o4 differ only by the integration variable, it is difficult to see in what sense the solution is correct. The expected solution is, of course, something like V = V0 * exp(-'integrate(kappa(p1), p1, p0, p)). Even worse are the substitutions when the values for the integration variables are non-atomic: (%i6) ic1(sol, V = V0, p = p0 + p1); / / [ [ I kappa(p1 + p0) dp1 + p0 - I kappa(p) dp ] ] / / (%o6) V = %e V0 At least the printer should be modified to give d(p1+p0), or even dp1 + dp0, for a non-atomic integration variable. I have not tested whether ic2 misbehaves in an analogous manner. A. Reiner, . ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1789213&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-1789213 ] ic1 for solution containing indefinite integral From: SourceForge.net - 2008-06-15 00:51:52 ```Bugs item #1789213, was opened at 2007-09-06 02:48 Message generated for change (Settings changed) made by robert_dodier You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1789213&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: Share Libraries Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: ic1 for solution containing indefinite integral Initial Comment: It seems that ic1(s, x, y) fails to produce a meaningful result when s involves an indefinite integral. Example: (%i2) sol: ode2(kappa(p) = -'diff(V, p) / V, V, p); / [ - I kappa(p) dp ] / (%o2) V = %c %e (%i3) ic1(sol, p = p0, V = V0); / / [ [ I kappa(p0) dp0 - I kappa(p) dp ] ] / / (%o3) V = %e V0 (%i4) ic1(sol, V = V0, p = p0); / / [ [ I kappa(p0) dp0 - I kappa(p) dp ] ] / / (%o4) V = %e V0 As the two integrals in %o3 and %o4 differ only by the integration variable, it is difficult to see in what sense the solution is correct. The expected solution is, of course, something like V = V0 * exp(-'integrate(kappa(p1), p1, p0, p)). Even worse are the substitutions when the values for the integration variables are non-atomic: (%i6) ic1(sol, V = V0, p = p0 + p1); / / [ [ I kappa(p1 + p0) dp1 + p0 - I kappa(p) dp ] ] / / (%o6) V = %e V0 At least the printer should be modified to give d(p1+p0), or even dp1 + dp0, for a non-atomic integration variable. I have not tested whether ic2 misbehaves in an analogous manner. A. Reiner, . ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1789213&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-1789213 ] ic1 for solution containing indefinite integral From: SourceForge.net - 2010-10-12 20:28:07 ```Bugs item #1789213, was opened at 2007-09-06 10:48 Message generated for change (Comment added) made by crategus You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1789213&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: Share Libraries Group: None >Status: Closed >Resolution: Fixed Priority: 5 Private: No Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: ic1 for solution containing indefinite integral Initial Comment: It seems that ic1(s, x, y) fails to produce a meaningful result when s involves an indefinite integral. Example: (%i2) sol: ode2(kappa(p) = -'diff(V, p) / V, V, p); / [ - I kappa(p) dp ] / (%o2) V = %c %e (%i3) ic1(sol, p = p0, V = V0); / / [ [ I kappa(p0) dp0 - I kappa(p) dp ] ] / / (%o3) V = %e V0 (%i4) ic1(sol, V = V0, p = p0); / / [ [ I kappa(p0) dp0 - I kappa(p) dp ] ] / / (%o4) V = %e V0 As the two integrals in %o3 and %o4 differ only by the integration variable, it is difficult to see in what sense the solution is correct. The expected solution is, of course, something like V = V0 * exp(-'integrate(kappa(p1), p1, p0, p)). Even worse are the substitutions when the values for the integration variables are non-atomic: (%i6) ic1(sol, V = V0, p = p0 + p1); / / [ [ I kappa(p1 + p0) dp1 + p0 - I kappa(p) dp ] ] / / (%o6) V = %e V0 At least the printer should be modified to give d(p1+p0), or even dp1 + dp0, for a non-atomic integration variable. I have not tested whether ic2 misbehaves in an analogous manner. A. Reiner, . ---------------------------------------------------------------------- >Comment By: Dieter Kaiser (crategus) Date: 2010-10-12 22:28 Message: Fixed in ode2.mac revision 1.6. Closing this bug report as fixed. Dieter Kaiser ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1789213&group_id=4933 ```