# odeset

Specify ordinary differential equation options.

## Syntax

options = odeset('option1', value1, 'option2', value2)

## Inputs

`optionN`- The name of option N to set.
`valueN`- The value or string to set for option N.

## Outputs

- options
- A struct containing the options

## Examples

`options = odeset('RelTol', 1.0e-3, 'AbsTol', 1.0e-6)`

```
options = struct [
AbsTol: 1e-06
RelTol: 0.001
]
```

`options = odeset('Jacobian', @JacFunc)`

```
options = struct [
Jacobian: JacFunc
]
```

## Comments

The default value for RelTol is 1.0e-3. It is a scalar.

The default value for AbsTol is 1.0e-6. It can be specified as either a scalar that applies to every equation in the system, or as a vector with one element for each equation.

The default value for MaxStep is Inf.

The 'Events' function is often used to locate roots of the system of equations. The function
inputs will be the same as the required system function inputs. An example follows which specifies two events
to locate roots in the system of equations.
function [value,isterminal,direction] = myEvent(t,y)
value = [y(1) y(2)];
isterminal = [0 0];
direction = [0 0];
end
The `value` output contains the events to be triggered when a zero occurs, such as a function root.
The `isterminal` output is set to:
1 - if a triggered event should terminate execution.
0 - otherwise.
The `direction` output is set to:
0 - if all zeros that occur at an event index are to be detected.
1 - if only zeros of increasing events are to be detected.
-1 - if only zeros of decreasing events are to be detected.
The outputs should be all scalars, or vectors with the same length.