8.8.4 Specifying the positioning of axes

By default, the x1-axis is placed along the bottom of graphs and the y1-axis is placed up the left-hand side of graphs. On three-dimensional plots, the z1-axis is placed at the front of the graph. The second set of axes are placed opposite the first: the x2-, y2- and z2-axes are placed respectively along the top, right and back sides of graphs. Higher-numbered axes are placed alongside the x1-, y1- and z1-axes.

However, the position of any axis can be explicitly set using syntax of the form:

set axis x top
set axis y right
set axis z back

Horizontal axes can be set to appear either at the top or bottom; vertical axes can be set to appear either at the left or right; and -axes can be set to appear either at the front or back.