## 1.8.5 Configuring the appearance of axes

The `set axis` command also accepts the following keywords alongside the positional keywords listed above, which specify how the axis should appear:

- `arrow` – Specifies that an arrowhead should be drawn on the right/top end of the axis. [Not default].

- `atzero` – Specifies that rather than being placed along an edge of the plot, the axis should mark the lines where the perpendicular axes `x1`, `y1` and/or `z1` are zero. [Not default].

- `automirrored` – Specifies that an automatic decision should be made between the behaviour of `mirrored` and `nomirrored`. If there are no axes on the opposite side of the graph, a mirror axis is produced. If there are already axes on the opposite side of the graph, no mirror axis is produced. [Default].

- `fullmirrored` – Similar to `mirrored`. Specifies that this axis should have a corresponding twin placed on the opposite side of the graph with mirroring ticks and labelling. [Not default; see `automirrored`].

- `invisible` – Specifies that the axis should not be drawn; data can still be plotted against it, but the axis is unseen. See Example 1.11.2 for a plot where all of the axes are invisible.

- `linked` – Specifies that the axis should be linked to another axis; see Section 1.8.9.

- `mirrored` – Specifies that this axis should have a corresponding twin placed on the opposite side of the graph with mirroring ticks but with no labels on the ticks. [Not default; see `automirrored`].

- `noarrow` – Specifies that no arrowheads should be drawn on the ends of the axis. [Default].

- `nomirrored` – Specifies that this axis should not have any corresponding twins. [Not default; see `automirrored`].

- `notatzero` – Opposite of `atzero`; the axis should be placed along an edge of the plot. [Default].

- `notlinked` – Specifies that the axis should no longer be linked to any other; see Section 1.8.9. [Default].

- `reversearrow` – Specifies that an arrowhead should be drawn on the left/bottom end of the axis. [Not default].

- `twowayarrow` – Specifies that arrowheads should be drawn on both ends of the axis. [Not default].

- `visible` – Specifies that the axis should be displayed; opposite of `invisible`. [Default].

The following simple examples demonstrate the use of some of these configuration options:

    set axis x atzero twoway
    set axis y atzero twoway
    plot [-2:8][-10:10]

    set axis x atzero arrow
    set axis y atzero twoway
    plot [0:10][-10:10]

    set axis x notatzero arrow nomirror
    set axis y notatzero arrow nomirror
    plot [0:10][0:20]