Simulation options¶

These following options exists for the integrators. Some options are only relevant for the IDA integrator. The options are stored as a Dict in SimulationObject.options.

How to set the simulation options¶

The easiest way to interact with the options is to use the get function get_options() to fetch the options dictionary, change the desired options (for instance the absolute simulation tolerance abs_tol and the relative simulation tolerance rel_tol), and the update the simulation object with these new options using the set function set_options(options: Dict[str, float]). See example below.

options = simulation_object.get_options()
options['abs_tol'] = 1e-8
options['rel_tol'] = 1e-10
simulation_object.set_options(options)

Alternative, you can alter the option directly by passing a custom dictionary, see example below:

options = {'abs_tol': 1e-8, 're_tol': 1e-10}
simulation_object.set_options(options)

The next sections describe the existing CVODE options and IDA options that you can interact with through the simulation object options.

CVODE options¶

Option	Type	Default value	Description
`abs_tol`	`float`	`1.0e-6`	The scalar absolute error tolerance
`init_step`	`float`	`0.0`	The value of the initial step size to be attempted
`max_conv_fails`	`int`	`10`	Maximum number of allowable nonlinear solver convergence failures per step
`max_err_test_fails`	`int`	`50`	Maximum number of error test failures allowed on one step
`max_hnil`	`int`	`-1`	Maximum number of messages issued by the solver warning that t + h = t on the next internal step
`max_nonlin_iters`	`int`	`3`	Maximum number of nonlinear solver iterations allowed per step
`max_num_steps`	`int`	`100000`	maximum number of steps to be taken by the solver in its attempt to reach the next output time
`max_ord`	`int`	`5`	Maximum order of the linear multistep method. Must be positive
`max_step`	`float`	`0.0`	Upper bound on the magnitude of the step size
`method`	`int`	`0`	Linear multistep method. 0 for Adams, 1 for BDF
`min_step`	`float`	`0.0`	Lower bound on the magnitude of the step size
`rel_tol`	`float`	`1.0e-6`	The scalar relative error tolerance
`show_integrator_stats`	`int`	`0`	If set to 1, prints diagnostic statistics for the simulation

IDA options¶

Option	Type	Default value	Description
`abs_tol`	`float`	`1.0e-6`	The scalar absolute error tolerance The scalar absolute error tolerance
`calc_ic`	`int`	`0`	If set to 1, will correct initial conditions prior to simulation.
`init_step`	`float`	`0.0`	The value of the initial step size to be attempted
`max_conv_fails`	`int`	`10`	Maximum number of allowable nonlinear solver convergence failures per step
`max_err_test_fails`	`int`	`50`	Maximum number of error test failures allowed on one step
`max_nonlin_iters`	`int`	`3`	Maximum number of nonlinear solver iterations allowed per step
`max_num_backs_ic`	`int`	`100000`	Maximum number of linesearch backtracks allowed in any Newton iteration, when solving the initial conditions calculation problem
`max_num_iters_ic`	`int`	`10000`	Maximum number of Newton iterations allowed in any one attempt to solve the initial conditions calculation problem
`max_num_jacs_ic`	`int`	`5000`	Maximum number of the approximate Jacobian or preconditioner evaluations allowed when the Newton iteration appears to be slowly converging
`max_num_steps`	`int`	`100000`	Maximum number of steps to be taken by the solver in its attempt to reach the next output time
`max_num_steps_ic`	`int`	`5000`	Maximum number of steps to be taken by the solver when correcting the initial conditions. See calc_ic.
`max_ord`	`int`	`5`	Maximum order of the linear multistep method. Must be positive
`max_step`	`float`	`0.0`	Maximum absolute value of the step size
`rel_tol`	`float`	`1.0e-6`	The scalar relative error tolerance
`show_integrator_stats`	`int`	`0`	If set to 1, prints diagnostic statistics for the simulation