NMath Reference Guide

## Variable |

Class containing available options for the VariableOrderOdeSolver.

Inheritance Hierarchy

Syntax

The VariableOrderOdeSolverOptions type exposes the following members.

Constructors

Name | Description | |
---|---|---|

VariableOrderOdeSolverOptions | Constructs a VariableOrderOdeSolver.Options instance, setting all options to their default. |

Properties

Name | Description | |
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AbsoluteTolerance | Gets and sets the bound on the estimated error at each integration step. | |

ConstantJacobian | Gets and sets a matrix which is the constant Jacobian of the function f in the differential equation y' = f(t,y). If no matrix is specified the algorithm will check to see if a jacobian function is specified and if so use it. Otherwise jacobian is numerically computed. | |

InitialStepSize | Suggested initial step size. The solver will try this first. By default the solver determines an initial step size automatically. | |

JacobianFunction | Gets and sets a function for computing the Jacobian of the function f in the differential equation y' = f(t,y). If no function is specified the algorithm will check to see if a constant jacobian is specified and if so use it. Otherwise jacobian is numerically computed. | |

MassMatrix | Gets and sets the Mass matrix M for problems of the form M*y' = F(t,y) where M is a matrix of constant values. | |

MassMatrixFunction | Gets and sets the time-state dependent Mass matrix M(t,y) for problems of the form M(t,y)*y' = F(t,y) | |

MaxOrder | Maximum order formula used to compute the solution. Default value is 5; | |

MaxStepSize | Upper bound on step size. Defaults to one-tenth of the times span interval. | |

NormControl | Control error relative to norm of solution. If true the solver controls the error, e, in the solution, y, at each integration step by norm(e) <= max(RelativeTolerance*norm(y), AbsoluteTolerance) Default value is false. | |

OutputFunction | Gets and sets the delegate for the output function. | |

Refine | Increases the number of output points by the specified factor producing smoother output. If Refine is n which is greater than 1, the solver subdivides each time step into n smaller intervals and returns solutions at each time point. The extra values produced for Refine are computed by means of continuous extension formulas The default for RungeKutta45OdeSolver solver is 4. | |

RelativeTolerance | Bound on the estimated error at each integration step. At the ith integration step the error, e[i] for the estimated solution y[i] satisfies e[i] <= max(RelativeTolerance*Math.Abs(y[i]), AbsoluteTolerance[i]) | |

UseBackwardDifferention | Rosenbrock32stiff is a variable-order solver for stiff problems. It is based on the numerical differentiation formulas (NDFs). The NDFs are generally more efficient than the closely related family of backward differentiation formulas (BDFs), also known as Gear's methods. The ode15s properties let you choose among these formulas, as well as specifying the maximum order for the formula used. |

Fields

Name | Description | |
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DefaultAbsTolerance | Default value for the absolute error tolerance. |

See Also