nelson.ode.options.ODE15i

📄Description

nelson.ode.options.ODE15i creates a compatible option class for the 'ode15i' solver value used by the ode object workflow.

Option group	Names	Purpose
Steps	InitialStep, MaxStep, MinStep	Bound the adaptive step size selection.
Error control	NormControl	Switch between componentwise and norm based error control.
Method	MaxOrder	Bound the order of the backward differentiation formulas.
Consistent initials	ComputeConsistentInitialConditions	Request consistent y0 and yp0 before integration.
Evaluation	Vectorization	Declare vectorization of the residual function with respect to y and yp.
Output	OutputFcn, OutputSelection	Select output callbacks and returned components.

The 'ode15i' solver value uses a variable order implicit method for fully implicit residual problems F(t,y,yp)=0, including stiff differential algebraic equations.

Supported properties are InitialStep, MaxStep, MinStep, NormControl, OutputFcn, OutputSelection, Vectorization, MaxOrder, and ComputeConsistentInitialConditions. InitialStep, MaxStep, and MinStep are positive scalars bounding the adaptive step size; their default value is empty, which lets the solver choose them automatically. NormControl accepts 'on' or 'off' (default 'off') and enables error control based on the norm of the solution instead of componentwise control. Vectorization is a two-element cell array such as {'off', 'off'} (the default) declaring vectorization of the residual function with respect to y and yp; a single 'on' or 'off' value applies to both arguments. MaxOrder is an integer between 1 and 5 (default 5) bounding the order of the formulas. ComputeConsistentInitialConditions is a logical scalar (default true); when enabled, the solver adjusts the initial value and initial slope so that the residual is consistent at the initial time. OutputFcn is a function handle called on each output point (default empty). OutputSelection is a vector of indices selecting which solution components are passed to the output function (default empty, all components). The default Refine value for this solver is 1.

💡Examples

Create a fully implicit residual problem solved with ode15i options.

options = nelson.ode.options.ODE15i('MaxOrder', 4);
problem = ode('EquationType', 'fullyimplicit', ...
  'ODEFcn', @(t,y,yp) yp + y, ...
  'InitialValue', 1, ...
  'InitialSlope', -1, ...
  'SolverOptions', options);
result = solve(problem, 0, 1)