Usage
simulate (type="DYNAMICS", start=0.0, end=None, duration=None,
dtout=None, steps=None, dsa="", start=None, print_increment=None, constraint_tol=None,
implicit_diff_tol=None, onOutputStep =None, returnResults=False, output="on")
Attributes
- type
- String
- Defines the type of analysis to be performed. You must select one from:
- "Static"
- "Dynamics"
- "Linear"
- "Assembly"
- type is optional. When not specified,
type is set to "DYNAMICS"
- start
- Double
- Defines the starting time value for a simulation.
- This attribute is optional. start defaults to 0.0 when
not specified.
- end
- Defines the end time for a simulation.
- duration and end are mutually
exclusive. Only one of these must always be specified.
- 0 ≤ start < end
- duration
- Double
- Specifies the duration of the analysis. Thus end =
start + duration
- duration and end are mutually
exclusive. Only one of these must always be specified.
- duration > 0
- dtout
- Double
- Defines the time interval between consecutive output steps for plotting and
animation output.
- dtout is optional. Defaults to 0.01
when not specified.
- When specified, dtout > 0
- Note that the maximum integrator step size (HMAX) is set
to the dtout if dtout is smaller than
HMAX.
- steps
- Integer
- Defines the number of output steps to take between start
and end.
- steps and dtout are mutually
exclusive. Only one of these must always be specified.
- When specified, steps > 0.
- dtout will be determined as
(end-start)/steps.
- Note that the maximum integrator step size (HMAX) is set
to the dtout if dtout is smaller than
HMAX.
- dsa
- String
- Defines the type of design sensitivity analysis to perform in conjunction
with the analysis. When specified you must select one of:
- "Auto": MotionSolve
will determine the best algorithm to use for computing design
sensitivities
- "Adjoint": MotionSolve
will use the Adjoint method for computing design sensitivities. This
method is recommended when there a lot of design variables and only
a few responses.
- "Direct": MotionSolve
will use the Direct Differentiation method for computing design
sensitivities. This method is recommended when there a few design
variables and but many responses.
- dsa is optional. When it is not specified, no design
sensitivity analysis is done. Design sensitivity analysis can be expensive.
So you should specify dsa only when you need it.
- start
- Double
- Currently unsupported.
- print_increment
- Double
- Specifies the frequency of output in terms of the integrator steps that have
been taken. An output is performed when the
function:
mod (integration_step_number, print_increment) = 0.
- print_increment is optional.
- When specified, print_increment > 0
- print_increment = 1 generates outputs at every
integration step
- print_increment = n generates outputs at every
nth integration step
- constraint_tol
- Double
- Specifies the accuracy to which the simulation is required to satisfy the
constraints (Joints, Jprims, Motions, etc.) in the model.
- constraint_tol is optional.
- implicit_diff_tol
- Double
- Specifies the accuracy to which the implicit differential equations in your
model are satisfied. These are the DIFFs in your model that have
implicit = True.
- The argument implicit_diff_tol is optional. When not
specified, implicit_diff_tol = 1.0E-5.
- onOutputstep
- Python function
- This is a callback function that will be invoked when the solver hits an
output step. It can be used for animation, live plots etc..
- returnResults
- Boolean
- returnResults is a boolean that, if True, causes the
simulate command to return a data structure filled with results.
Examples
# Create a model
m = CreateStewartPlatform (output="Stewart-Platform")
# Do a static analysis first
m.simulate (type="Statics", returnResults=True)
# Then do a dynamic analysis
run=m.simulate (type="DYNAMICS", end=1.77, dtout=0.01, returnResults=True)
Having defined returnResults to True causes the run object to be
populated with output data from the simulation. By default, Bodies transformations,
Request and Response Variables generate the output that populates the run
object.