### 27.2.1 Drawing unit vectors

The Ox_3d_unit_vector command takes no arguments and draws the unit vector in the x-direction on a 3D graphic screen.

#### Example

Ox_3d_unit_vector()

Similarly, the Oy_3d_unit_vector and Oz_3d_unit_vector commands draw the unit vector in the y and z directions, respectively.

These commands have no parameters, but can be decorated with the legend command.

#### Example

Ox_3d_unit_vector(),legend(point([1,0,0]),"unit x vector",blue)

The frame_3d command draws all three vectors simultaneously.

#### Example

frame_3d()