executive_control set dynamics_parameters integrator_parameters
The EXECUTIVE_CONTROL SET DYNAMICS_PARAMETERS INTEGRATOR_PARAMETERS command controls parameters common to multiple integrators.
Description:
Parameter | Value Type | Description |
|---|
model_name | AN EXISTING MODEL | Specifies the model to be modified. You use this parameter to identify the existing model to be affected with this command. |
relative_error | Real | Specifies a relative error tolerance for the integrator |
absolute_error | Real | Specifies the absolute error tolerance for the integrator. The absolute error tolerance will by bounded by the value of ABSOLUTE_ERROR. |
error_scaling | Real number | Real number should be > 0. Can take 1-16 values. |
continue_on_failure | Yes/no | When the CONTINUE_ON_FAILURE argument is set to YES, it allows the code to continue the simulation with a set of relaxed error tolerances when the specified conditions cannot be met. Otherwise, when set to NO, the control of the Adams simulation will be returned to the command level. |
step_maximum | Integer | The maximum number of integration steps that the code will take between output steps. |
init_time_step | Real number | Real number should be > 0 |
max_time_step | Real number | Real number should be > 0 |
min_time_step | Real number | Real number should be > 0 |
max_integrator_order | Integer | Integer should be greater than 0 and less than or equal to 12 |
interpolate | Yes/No | Indicates whether interpolation is allowed. That is, indicates whether the integrator can choose integration steps independent of output steps and the interpolate results for the output step times. |
watch_integrator_perf | MONITOR, NO_MONITOR, ERROR_IN_INTEGRATOR, NO_ERROR_IN_INTEGRATOR, FAILURE_IN_INTEGRATOR, NO_FAILURE_IN_INTEGRATOR, STEPSIZE, NO_STEPSIZE, NEWSTEP, NO_NEWSTEP, OUTPUT, NO_OUTPUT, ALL, NONE | Provides the user with a means for observing the progress of the simulation by causing Adams to write information about the status and performance of the integration to the screen. |
reconcile | ALL, DISPLACEMENTS, NONE | Corrects interpolated results before Adams writes them to the output files to satisfy the constraint equations. |
Extended Definition:
1. You may identify a model by typing its name or by picking it from the screen.
If the model is not visible on the screen, you must type the name. You may also find it convenient to type the name even if the model is displayed.
You must separate multiple model names by commas.
If the model is visible in one of your views, you may identify it by picking on any of the graphics associated with it.
You need not separate multiple model picks by commas.
2. The relative error tolerance will be bounded by a minimum of:
■RELATIVE_ERROR, if a value is specified for it.
■(5.0 * 0.1**r), where r is the value specified by the command
>> EXECUTIVE_CONTROL SET EASY_DYNAMICS &
>& MODEL_NAME = <model_name> &
>& DIGITS_OF_PRECISION = r
if no value is specified for RELATIVE_ERROR.
3. After STEP_MAXIMUM integration steps, the simulation will stop and return to the command level. This feature is provided as a precaution against a simulation that is taking too much CPU time.
4. The WATCH_INTEGRATOR_PERF argument only affects diagnostics, not results.
The values can be:
MONITOR: The time, step size, and function-evaluation count at ten equally spaced output times during the simulation.
ERROR_IN_INTEGRATOR: The integration error after every time step.
FAILURE_IN_INTEGRATOR: The integration error when the code has to repeat the step because the calculated solution failed to meet the error criteria.
STEPSIZE: The step size and order after every integration step.
NEWSTEP: The step size and order only when the values are changed.
OUTPUT: An indication that another output record is being written to the output files.
ALL: All options are on.
NONE: All options are off.
5. The values for RECONCILE can be:
DISPLACEMENTS: Only the displacements are corrected to satisfy the constraints.
ALL: The displacements are corrected to satisfy the constraints and the velocities and accelerations are corrected to satisfy the constraint derivatives.
NONE: The integration step size is adjusted to force the integrator to compute the solution at every output step. In this situation, INTERPOLATE must be set to NO.
Cautions:
1. Note that interpolation is not yet available when the EXECUTIVE_CONTROL SET DYNAMICS_PARAMETERS BDF_PARAMETER command specifies FIXED or VARIABLE coefficients for the PREDICTOR_COEFFICIENTS argument.