NDSolve: What is the solution to the error ???
- To: mathgroup at smc.vnet.net
- Subject: [mg31670] NDSolve: What is the solution to the error ???
- From: fannews at email.com (Steve)
- Date: Fri, 23 Nov 2001 05:47:07 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Hi there, Would appreciate if someone could help me find the solution to the error of: NDSolve::ndnum: Encountered non-numerical value for a derivative at T== 0.`. You will face division by error due to the initial conditions, but is there anything I can do if I want the initial conditions = 0 ?? If nothing can be done, its ok for non-zero initial conditions. But how to solve the above error?? This may be a silly mistake that I made somewhere, but I can't seem to find it .... Many Thanks in advance :) Here is the code, copy & paste below to Mathematica: \!\(\* RowBox[{"NDSolve", "[", RowBox[{ RowBox[{"{", RowBox[{ RowBox[{ RowBox[{\(4\ Cos[\[CapitalLambda]\_3[T]]\), "-", \(\(484\ a\_1[T]\)\/483\), "+", \(\(114081221\ a\_1[T]\^3\)\/150238116\), "-", \(Sin[\[CapitalPhi]\_3[T]]\ a\_2[T]\), "+", \(484\/161\ a\_1[T]\ a\_2[T]\^2\), "+", \(242\/161\ Cos[2\ \[CapitalPhi]\_3[T]]\ a\_1[ T]\ a\_2[T]\^2\), "+", \(Cos[\[CapitalPhi]\_3[ T]]\ \((a\_2[ T] - \(234256\ a\_1[T]\^2\ a\_2[T]\)\/77763 - 3\/2\ a\_2[T]\^3)\)\), "+", RowBox[{"22", " ", \(a\_1[T]\), " ", RowBox[{"(", RowBox[{\(34\/3\), "-", RowBox[{ SubsuperscriptBox["\[CapitalLambda]", "3", "\[Prime]", MultilineFunction->None], "[", "T", "]"}]}], ")"}]}]}], "==", "0"}], ",", RowBox[{ RowBox[{\(4\ Sin[\[CapitalLambda]\_3[T]]\), "-", \(\(15961\ a\_1[T]\)\/483\), "+", \(Cos[\[CapitalPhi]\_3]\ a\_2[T]\), "+", \(242\/161\ Sin[2\ \[CapitalPhi]\_3[T]]\ a\_1[ T]\ a\_2[T]\^2\), "+", \(Sin[\[CapitalPhi]\_3[ T]]\ \((a\_2[ T] - \(234256\ a\_1[T]\^2\ a\_2[T]\)\/77763 - 3\/2\ a\_2[T]\^3)\)\), "-", RowBox[{"22", " ", RowBox[{ SubsuperscriptBox["a", "1", "\[Prime]", MultilineFunction->None], "[", "T", "]"}]}]}], "==", "0"}], ",", RowBox[{ RowBox[{\(\(117128\ a\_1[T]\^2\ a\_2[T]\)\/25921\), "+", \(\(239936708\ Cos[ 2\ \[CapitalPhi]\_3[T]]\ a\_1[T]\^2\ a\_2[ T]\)\/106146495\), "+", \(9\/4\ a\_2[T]\^3\), "+", RowBox[{\(Sin[\[CapitalPhi]\_3[T]]\), " ", RowBox[{"(", RowBox[{\(\(5324\ a\_1[T]\)\/161\), "+", RowBox[{\(22\/483\), " ", RowBox[{ SubsuperscriptBox["a", "1", "\[Prime]", MultilineFunction->None], "[", "T", "]"}]}]}], ")"}]}], "+", RowBox[{\(Cos[\[CapitalPhi]\_3[T]]\), " ", RowBox[{"(", RowBox[{\(-\(\(28344976\ a\_1[T]\^3\)\/12519843\)\), "-", \(726\/161\ a\_1[T]\ a\_2[T]\^2\), "-", RowBox[{\(22\/483\), " ", \(a\_1[T]\), " ", RowBox[{"(", RowBox[{\(34\/3\), "-", RowBox[{ SubsuperscriptBox["\[CapitalLambda]", "3", "\[Prime]", MultilineFunction->None], "[", "T", "]"}]}], ")"}]}]}], ")"}]}], "+", RowBox[{\(a\_2[T]\), " ", RowBox[{"(", RowBox[{\(97\/3\), "-", RowBox[{ SubsuperscriptBox["\[CapitalLambda]", "3", "\[Prime]", MultilineFunction->None], "[", "T", "]"}], "+", RowBox[{ SubsuperscriptBox["\[CapitalPhi]", "3", "\[Prime]", MultilineFunction->None], "[", "T", "]"}]}], ")"}]}]}], "==", "0"}], ",", RowBox[{ RowBox[{\(\(-\(3\/2\)\)\ a\_2[T]\), "-", \(\(239936708\ Sin[ 2\ \[CapitalPhi]\_3[T]]\ a\_1[T]\^2\ a\_2[ T]\)\/106146495\), "+", RowBox[{\(Cos[\[CapitalPhi]\_3[T]]\), " ", RowBox[{"(", RowBox[{\(\(5324\ a\_1[T]\)\/161\), "+", RowBox[{\(22\/483\), " ", RowBox[{ SubsuperscriptBox["a", "1", "\[Prime]", MultilineFunction->None], "[", "T", "]"}]}]}], ")"}]}], "-", RowBox[{ SubsuperscriptBox["a", "2", "\[Prime]", MultilineFunction->None], "[", "T", "]"}], "-", RowBox[{\(Sin[\[CapitalPhi]\_3[T]]\), " ", RowBox[{"(", RowBox[{\(-\(\(28344976\ a\_1[T]\^3\)\/12519843\)\), "-", \(726\/161\ a\_1[T]\ a\_2[T]\^2\), "-", RowBox[{\(22\/483\), " ", \(a\_1[T]\), " ", RowBox[{"(", RowBox[{\(34\/3\), "-", RowBox[{ SubsuperscriptBox["\[CapitalLambda]", "3", "\[Prime]", MultilineFunction->None], "[", "T", "]"}]}], ")"}]}]}], ")"}]}]}], "==", "0"}], ",", \(a\_1[0] == 0\), ",", \(a\_2[0] == 0\), ",", \(\[CapitalLambda]\_3[0] == 0\), ",", \(\[CapitalPhi]\_3[0] == 0\)}], "}"}], ",", \({a\_1, a\_2, \[CapitalLambda]\_3, \[CapitalPhi]\_3}\), ",", \({T, 0, 10}\), ",", RowBox[{"MaxSteps", "->", InterpretationBox["\[Infinity]", DirectedInfinity[ 1]]}], ",", \(Method -> RungeKutta\), ",", \(WorkingPrecision -> 16\)}], "]"}]\)