## maxima-bugs

 [Maxima-bugs] [ maxima-Bugs-1839088 ] ic2 fails with division by 0 From: SourceForge.net - 2007-11-27 00:54:32 ```Bugs item #1839088, was opened at 2007-11-26 19:54 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=1839088&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 - Differential eqns Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: John D. Ramsdell (ramsdell) Assigned to: Nobody/Anonymous (nobody) Summary: ic2 fails with division by 0 Initial Comment: I'm a beginner, but I think I found a bug in ic2. There should be a solution with x>=0 and y>0. \$ maxima Maxima 5.12.0 http://maxima.sourceforge.net Using Lisp GNU Common Lisp (GCL) GCL 2.6.7 (aka GCL) Distributed under the GNU Public License. See the file COPYING. Dedicated to the memory of William Schelter. This is a development version of Maxima. The function bug_report() provides bug reporting information. (%i1) y*'diff(y,x,2)=a; 2 d y (%o1) y --- = a 2 dx (%i2) ode2(%,y,x); - %k1 sqrt(%pi) %e sqrt(- a) erf(sqrt(- log(y) - %k1)) (%o2) [- ----------------------------------------------------- = x + %k2, sqrt(2) a - %k1 sqrt(%pi) %e erf(sqrt(- log(y) - %k1)) - ------------------------------------------- = x + %k2] sqrt(2) sqrt(- a) (%i3) ic2(%,x=0,y=b,diff(y,x)=0); Division by 0 #0: ic2(soln=[-sqrt(%pi)*%e^-%k1*sqrt(-a)*erf(sqrt(-log(y)-%k1))/(sqrt(2)*a) = x+%k2,-sqrt(%pi)*%e^-%k1*erf(sqrt(...,xa=x = 0,ya=y = b,dya=0 = 0)(ode2.mac line 320) -- an error. To debug this try debugmode(true); (%i4) quit(); \$ ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1839088&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-1839088 ] ic2 fails with division by 0 From: SourceForge.net - 2010-10-12 18:11:03 ```Bugs item #1839088, was opened at 2007-11-27 01:54 Message generated for change (Comment added) made by crategus You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1839088&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 - Differential eqns Group: None >Status: Closed >Resolution: Fixed Priority: 5 Private: No Submitted By: John D. Ramsdell (ramsdell) Assigned to: Nobody/Anonymous (nobody) Summary: ic2 fails with division by 0 Initial Comment: I'm a beginner, but I think I found a bug in ic2. There should be a solution with x>=0 and y>0. \$ maxima Maxima 5.12.0 http://maxima.sourceforge.net Using Lisp GNU Common Lisp (GCL) GCL 2.6.7 (aka GCL) Distributed under the GNU Public License. See the file COPYING. Dedicated to the memory of William Schelter. This is a development version of Maxima. The function bug_report() provides bug reporting information. (%i1) y*'diff(y,x,2)=a; 2 d y (%o1) y --- = a 2 dx (%i2) ode2(%,y,x); - %k1 sqrt(%pi) %e sqrt(- a) erf(sqrt(- log(y) - %k1)) (%o2) [- ----------------------------------------------------- = x + %k2, sqrt(2) a - %k1 sqrt(%pi) %e erf(sqrt(- log(y) - %k1)) - ------------------------------------------- = x + %k2] sqrt(2) sqrt(- a) (%i3) ic2(%,x=0,y=b,diff(y,x)=0); Division by 0 #0: ic2(soln=[-sqrt(%pi)*%e^-%k1*sqrt(-a)*erf(sqrt(-log(y)-%k1))/(sqrt(2)*a) = x+%k2,-sqrt(%pi)*%e^-%k1*erf(sqrt(...,xa=x = 0,ya=y = b,dya=0 = 0)(ode2.mac line 320) -- an error. To debug this try debugmode(true); (%i4) quit(); \$ ---------------------------------------------------------------------- >Comment By: Dieter Kaiser (crategus) Date: 2010-10-12 20:11 Message: Fixed in ode2.mac revision 1.5 Closing this bug report as fixed. Dieter Kaiser ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1839088&group_id=4933 ```