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NDSolve::parpiv NDSolveValue::parpiv ParametricNDSolve::parpiv ParametricNDSolveValue::parpiv LinearSolve::parpiv LinearSolveFunction::parpiv

NDSolve::parpiv NDSolveValue::parpiv ParametricNDSolve::parpiv ParametricNDSolveValue::parpiv LinearSolve::parpiv LinearSolveFunction::parpiv

Details

  • This message is issued when NDSolve is performing structural analysis and detects that the mass matrix associated with the underlying differential algebraic equation may be singular.
  • Off[message] switches off the message; On[message] switches it on. For example: Off[NDSolve::parpiv].

Examples

Basic Examples  (3)

The following differential algebraic equation issues this message when performing structural analysis:

NDSolve uses the "Pantelides" method for structural analysis:

Use a different index-reduction method to reduce the system and solve the system:

This message can also come up when time-dependent PDEs without a time derivative are present. Consider the following example:

Note that the last equation does not have a time derivative for . When you solve the equation, you get the following message:

This can be fixed by adding a small time-dependent component for :

In some cases, this message can come up during time integration of finite element models in NDSolve. When this happens, it can help to set the IDA method to use a different linear solver method with the NDSolve option: