# localOdeIntegrator (1d, 2d, 3d)¶

The localOdeIntegrator is used to integrate a Algebraic Equations and evaluates a set of input nodalArrays and stores the ouput in one or more user-specified nodalArrays. The number of inputs and outputs are defined by the kind of Algebraic Equations being used for the Equation.

## Data¶

in (string vector, required)
Inputs 1 to N are nodalArrays which will be supplied to the source through the Equation block.
out (string vector, required)
Outputs 1 to N are nodalArrays which will contain the output of the Source.

## Parameters¶

relativeErrorTolerance (float)
The allowable error.
integrationScheme
Integration scheme to use. Allowable types are bulirschStoer, rk5 and rosenbrock. The integrations schemes are described in the boost, odeint library.

## Sub-Blocks¶

Equation
Defines the kind of source being solved. Equation in this case is actually a kind of Algebraic Equations. If multiple <Equation> blocks are defined then the results are added together to produce the output.

## Example¶

The following code block demonstrates the usage of thelocalOdeIntegrator combined with the exprHyperSrc source:

<Updater integrator>
kind = localOdeIntegrator1d
integrationScheme = bulirschStoer
onGrid = domain

relativeErrorTolerance = 0.1

in = [q]
out = [qnew]

<Equation gravity>
kind = exprHyperSrc
indVars = ["a","b"]
exprs = ["-x*b","x*a"]
</Equation>

</Updater>
`