naginterfaces.library.ode.dae_dassl_setup¶
- naginterfaces.library.ode.dae_dassl_setup(neq, maxord, jceval, hmax, h0, itol)[source]¶
dae_dassl_setup
is a setup function which must be called prior to the integratordae_dassl_gen()
, if the DASSL implementation of Backward Differentiation Formulae (BDF) is to be used.For full information please refer to the NAG Library document for d02mw
https://support.nag.com/numeric/nl/nagdoc_30.1/flhtml/d02/d02mwf.html
- Parameters
- neqint
The number of differential-algebraic equations to be solved.
- maxordint
The maximum order to be used for the BDF method. Orders up to 5th order are available; setting means that the maximum order used will be .
- jcevalstr, length 1
Specifies the technique to be used to compute the Jacobian.
The Jacobian is to be evaluated numerically by the integrator.
You must supply a function to evaluate the Jacobian on a call to the integrator.
Only the first character of the actual paramater is passed to
dae_dassl_setup
; hence it is permissible for the actual argument to be more descriptive, e.g., ‘Numerical’ or ‘Analytical’, on a call todae_dassl_setup
.- hmaxfloat
The maximum absolute step size to be allowed. Set if this option is not required.
- h0float
The step size to be attempted on the first step. Set if the initial step size is calculated internally.
- itolint
A value to indicate the form of the local error test.
and are single element vectors.
and are vectors. This should be chosen if you want to apply different tolerances to each equation in the system.
See
dae_dassl_gen()
.Note: the tolerances must either both be single element vectors or both be vectors of length .
- Returns
- commdict, communication object
Communication structure.
- Raises
- NagValueError
- (errno )
On entry, .
Constraint: .
- (errno )
On entry, .
Constraint: .
- (errno )
On entry, has an illegal value: .
Constraint: or .
- (errno )
On entry, .
Constraint: .
- (errno )
On entry, .
Constraint: or .
- Notes
This integrator setup function must be called before the first call to the integrator
dae_dassl_gen()
. This setup functiondae_dassl_setup
permits you to define options for the DASSL integrator, such as: whether the Jacobian is to be provided or is to be approximated numerically by the integrator; the initial and maximum step-sizes for the integration; whether relative and absolute tolerances are system wide or per system equation; and the maximum order of BDF method permitted.