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Execution settings🔗

Execution settings also known as Global simulation settings, consists of three execution types:

  • Type 1: Dynamic simulation settings
  • Type 2: Steady State simulation settings
  • Type 3: Custom settings

Each execution type, consists of same four (4) sections where variables are available specific for each execution type:

  • Section 1: Simulation Options
  • Section 2: Compiler Options
  • Section 3: Solver Options
  • Section 4: Runtime Options

Global vs Local simulation settings

Modelon Impact has two types of simulation settings:

  • Global simulation settings specify default simulation settings, are applied to all models and not stored in the model.
  • Local simulation settings specify simulation settings specific for a model and thus stored in the model. Local simulation settings are accessible in the Experimentation mode, under the EXPERIMENT tab and further down, the Analysis tab.

Simulation settings are grouped into:

  • Basic - common settings
  • Advanced - numerical settings
  • Global settings

Dynamic settings🔗

Dynamic Simulation Options🔗

Simulation framework options for solving the FMU using the Assimulo simulation package.

General options for the AssimuloFMIAlg algorithm
Default Description
filter None A filter for choosing which variables to store result for. filter = "*der" , store all variables ending with 'der' and filter = ["*der*", "summary*"], store all variables with "der" in the name and all variables starting with "summary".
ncp 500 Number of communication points. If ncp is zero, the solver will return the internal steps taken.
solver "CVode" Specifies the simulation method that is to be used. Currently supported solvers are, CVode, Radau5ODE, RungeKutta34, Dopri5, RodasODE, LSODAR, ExplicitEuler. The recommended solver is "CVode".
with_jacobian False Simulation with analytical Jacobian, Note: all models can't generate an analytical Jacobian.
write_scaled_result False When true, write the result to file without taking numerical scaling into account.
dynamic_diagnostics False If enabled, additional diagnostic variables will be included in the simulation results.

Dynamic Solver options🔗

Options for the chosen solver.

Selection of solver arguments for CVode
Option Default Description
disc 'BDF' Discretization method. Can be either 'BDF' or 'Adams'.
h 0.01 The step-size for ExplicitEuler solver.
iter 'Newton' The iteration method. Can be either 'Newton' or 'FixedPoint'.
maxord 5 The maximum order used. Maximum for 'BDF' is 5 while for the 'Adams' method the maximum is 12.
maxh Inf Maximum step-size.
rtol 1e-4 Relative tolerance. The relative tolerance is retrieved from the 'default experiment' section in the XMLfile and if not found is set to 1.0e-4.
atol rtol*0.01*(nominal values of the continuous states) Absolute Tolerance. Can be an array where each value corresponds to the absolute tolerance for the corresponding variable. Can also be a single value.

Dynamic Compiler options🔗

Compiler options specify with what options a model is compiled into an FMU.

Selection of compilation options
Option Default Description
c_compiler gcc C compiler. msvs= Microsoft Visual Studio Compiler.
msvs_path Path to the Microsoft Visual Studio Compiler to compile C code with. Will cause compilation to fail if no installation is found.
msvs_version Microsoft Visual Studio Compiler version or year edition to compile C code with. If the msvs_path option is not set, then this option will be used to find an installation among the default install locations. If the msvs_path option is set, then this option will be used to verify the compiler version. In both cases the compilation will fail if the installation found mismatches the version specified with this option.
generate_html_diagnostics false If enabled, model diagnostics are generated in HTML format. This includes the flattened model, connection sets, alias sets and BLT form.
include_protected_variables false Includes protected variables in the compilation target interface if the protection annotation on the class allows viewing variables.

Dynamic Runtime options🔗

+ Add new adds additional solver options. Detailed descriptions on how to add a solver option are found in the Optimica Compiler Toolkit (OCT) user guide.