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3.12 Nonlinear Simplification Techniques 405
If no SimulationFunction option is specified, the default function is used. The default DT
simulation function DefaultDTSimulation calls NDAESolve (Section 3.7.5) to calculate the DC
operating points. DefaultDTSimulation inherits almost all options from NDAESolve. The following
options have a special meaning when used with DefaultDTSimulation:
option name
default value
MaxIterations
Inherited[NDAESolve]
maximum number of iterations for
NDAESolve (only used if option
InitialGuess is set to Automatic)
InitialGuess None if set to Automatic, the values of the
reference simulation are used as initial
guess for NDAESolve
Options for DefaultDTSimulation.
Besides the default simulation function you can define your own DT simulation function and specify
it as SimulationFunction in the DT mode settings for NonlinearSetup. During the setup and the
nonlinear simplifications this function will be called with the following arguments:
simfct[dae_, refsim_List:{}, opts___]
Pattern for a user-defined DT simulation function.
Here, dae is a DC or Transient DAEObject, refsim is the list of numerical reference values and opts
are additional options.
The simulation function must return the DC operating points in the same format as NDAESolve
returns DC operating points of a parameter sweep (see Section 3.7.2).
Similarly, you can define your own DT error function instead of the default error function and
specify it as ErrorFunction in the DT mode settings for NonlinearSetup. During the simplification
routines this function is used to calculate the error with the following arguments:
errfct[newval_List, oldval_List, outputsymbols_List]
Pattern for a user-defined DT error function.
Here, newval and oldval are the numerical solutions of the simplified and the original DAE system,
outputsymbols is a list of all output symbols.
The error function must return a list of rules {symb
−> err , † † † }, which specifies the numerical error
for each output symbol. The default DT error function calculates the maximum absolute error.