NDSolve::eerr NDSolveValue::eerr ParametricNDSolve::eerr ParametricNDSolveValue::eerr

Details

  • This message is generated by excessive numerical error while solving a partial differential equation.
  • This error can sometimes be avoided by reducing the value of the StartingStepSize option to increase the number of grid points, or by lowering the value of the AccuracyGoal or PrecisionGoal option to increase the error tolerance.
  • This error can sometimes be avoided by using the "StiffnessSwitching" method. More information.
  • This error can sometimes be avoided by specifying a MaxStepSize.
  • Off[message] switches off the message; On[message] switches it on. For example: Off[NDSolve::eerr].

Examples

Basic Examples  (4)

The default choice for grid spacing is not sufficient for computing a solution to within the default error tolerance:

Lowering the value of the PrecisionGoal option raises the error tolerance:

The high differential order makes this problem stiff:

Solving with the "StiffnessSwitching" method resolves the issue:

Consider the following PDE:

Below is a plot of the solution at . It is apparent that the warning message is appropriate because the oscillations near the peak are not physical:

Reduce the MaxStepSize to resolve the fast changes of the solution at the front:

Alternatively, refine the grid with the options of "TensorProductGrid":

Solve a PDE:

Reduce the MaxStepSize to resolve the error message: