Changing ODE Integration Properties :: Differential Equations (Mathematics)

Mathematics

Changing ODE Integration Properties

The default integration properties in the ODE solvers are selected to handle common problems. In some cases, you can improve ODE solver performance by overriding these defaults. You do this by supplying the solvers with an options structure that specifies one or more property values.

For example, to change the value of the relative error tolerance of the solver from the default value of 1e-3 to 1e-4,

Create an options structure using the function odeset by entering

```
options = odeset('RelTol', 1e-4);
```

Pass the options structure to the solver as follows:

For all solvers except ode15i, use the syntax

[t,y] = solver(odefun,tspan,y0,options)

For ode15i, use the syntax

[t,y] = ode15i(odefun,tspan,y0,yp0,options)

For an example that uses the options structure, see Example: Stiff Problem (van der Pol Equation). For a complete description of the available options, see the reference page for odeset.

Example: Solving a Fully Implicit ODE Problem Examples: Applying the ODE Initial Value Problem Solvers