NDSolve::nderr NDSolveValue::nderr ParametricNDSolve::nderr ParametricNDSolveValue::nderr
Details
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- This message is generated by a specific type of failure within the algorithm that is used for solving initial value problems.
- This error can occur if the differential equation has singular or oscillatory solutions.
- If you see this message in an example where it is not expected, please contact Technical Support for more information.
- If you see this message in an example with WorkingPrecision greater than MachinePrecision try using the option Method->"StiffnessSwitching" in NDSolve.
- Off[message] switches off the message; On[message] switches it on. For example: Off[NDSolve::nderr].
Examples
Basic Examples (2)
Usually this message is generated when the starting step size is too big, and sometimes it is generated when the DAE is too high an index to solve:
![](Files/nderr.en/2.gif)
Starting with a very small step size helps:
The following differential equation cannot be solved:
![](Files/nderr.en/3.gif)
It appears that the equation is becoming stiff, and NDSolve is having a hard time detecting this and modifying the methods it chooses accordingly. You can get a solution by explicitly using Method"StiffnessSwitching". While this does work, it increases the computation time substantially:
Alternatively, since this is a boundary value problem, you can use the "Shooting" method to solve it faster. However, this is very sensitive to the choice for "StartingInitialConditions". Since there are two variables, obtaining a set of "StartingInitialConditions" that solves the problem may require substantial guessing and checking: