The function type for computing additional quantities based on the
solution, but which are not expressed in terms of derivatives. This
may be null, in which case no calculation will be done. Note that
unlike RhsFn, OutputFn returns the output rather than
writing to an array in-place.

The function type for computing additional quantities based on the solution, but which are not expressed in terms of derivatives. This may be

`null`

, in which case no calculation will be done. Note that unlike RhsFn,`OutputFn`

returns the output rather than writing to an array in-place.## See

RhsFn and OutputFnDelayed

## Param

The time

## Param

The solution at this point in time