It is possible to specify various options for the continuation run. In the continuation we use the options structure which is initially created with contset:
options = contset;
will initialize the structure. The continuer stores the handle to the options in the variable
cds.options.
Options can then be set using
options = contset(options, optionname, optionvalue);
where optionname is an option from the following list (the list is stored in the file contidx.m in the directory Continuer).
- InitStepsize
- the initial stepsize (default:
)
- MinStepsize
- the minimum stepsize to compute the next point on the curve (default:
)
- MaxStepsize
- the maximum stepsize (default:
)
- MaxCorrIters
- maximum number of correction iterations (default:
)
- MaxNewtonIters
- maximum number of Newton-Raphson iterations before switching to Newton-Chords in the corrector iterations (default:
)
- MaxTestIters
- maximum number of iterations to locate a zero of a testfunction (default:
)
- Increment
- the increment to compute first order derivatives numerically (default:
)
- FunTolerance
- tolerance of function values:
FunTolerance is the first convergence criterium of the Newton iteration (default:
)
- VarTolerance
- tolerance of coordinates:
VarTolerance is the second convergence criterium of the Newton iteration (default:
)
- TestTolerance
- tolerance of test functions (default:
)
- Singularities
- boolean indicating the presence of a singularity matrix (default:
)
- MaxNumPoints
- maximum number of points on the curve (default:
)
- Backward
- boolean indicating the direction of the continuation (sign of the initial tangent vector)
(default:
)
- CheckClosed
- number of points indicating when to start to check if the curve is closed (0 = do not check) (default:
)
- Adapt
- number of points after which to call the adapt-function while computing the curve (default:
=adapt always)
- IgnoreSingularity
- vector containing indices of singularities which are to be ignored (default: empty)
- Multipliers
- boolean indicating the computation of the multipliers (default:
)
- Eigenvalues
- boolean indicating the computation of the eigenvalues (default:
)
- TSearchOrder
- numerical value that indicates if unit vectors are cycled in increasing order of index (default:
, increasing) or
decreasing (set to a value different from
), see §3.4.10.
- Userfunctions
- boolean indicating the presence of user functions (default:
)
- UserfunctionsInfo
- is an array with structures containing information about the userfunctions. This structure has the following fields:
.label |
label of the userfunction |
.name |
name of this particular userfunction |
.state |
boolean indicating whether the userfunction has to be evaluated or not |
- PRC
- variable indicating the computation of the phase response curve (default: empty)
- dPRC
- variable indicating the computation of the derivative of the phase response curve (default: empty)
- Input
- vector representing the input given to the system for the computation of the phase response curve (default:
)
Options also contains some fields which are not set by the user but frozen or filled by calls
to the curvefile, namely:
- MoorePenrose
- boolean indicating the use of the Moore-Penrose continuation as the Newton-like corrector procedure (default:
)
- SymDerivative
- the highest order symbolic derivative which is present (default:
)
- SymDerivativeP
- the highest order symbolic derivative with respect to the free parameter(s) which is present (default:
)
- Testfunctions
- boolean indicating the presence of test functions (default:
)
- WorkSpace
- boolean indicating to initialize and clean up user variable space (default:
)
- Locators
- boolean vector indicating the user has provided his own locator code to locate zeroes of test functions. Otherwise the default locator will be used (default: empty)
- ActiveParams
- vector containing indices of the active parameter(s) (default: empty)
Some more details follow here on some of the options.