# Node ConstantNode

Defined in `mime.nodes.actuation._drive.ConstantNode`.

Algorithm `MIME-NODE-117`.

A command generator: the value it was built with, written into the command every step.

## Governing equations

$$
\mathbf{u}_{n} = \mathbf{c}
$$

## Discretisation

none declared; a node whose order depends on its construction declares it with the `discretization_order()` hook, which is read from a built node.

## Assumptions

- The value is the same at every step: it is a parameter of the graph, never a function of time or of anything the run computes

## Limitations

none declared

## Declared regimes (not evidenced here)

none declared

## References

none declared

## Symbols

| Symbol | Kind | Name | Units | Implemented by |
|---|---|---|---|---|
| $\mathbf{u}$ | state | `value` | the command's own (units declared, not checked) | `mime.nodes.actuation._drive.ConstantNode.advance` |
| $\mathbf{c}$ | parameter | `value` | the command's own (units declared, not checked) | `mime.nodes.actuation._drive.ConstantNode.advance` |

A row marked *units declared, not checked* has the units its author wrote: the code declares none there, so the node walk cannot compare them with anything.

## Built by

- [`drive.constant`](../entries/drive/drive.constant.md) 0.1.0