This routine sets the rotation angle for the *y* axis labels on
a linear, log or 3-D axis.
In order to provide a common interface to axes label angles some definitions
need to be made. We have defined positive* x* to be from left to right
and positive *y* and *z* (in a 3-D plot) to be from bottom to
top. The angle is in reference to the positive axis and increases in a
counter-clockwise direction. Above corresponds to positive angles, and
below corresponds to negative angles.
For example, in a normal *x*-*y* plot with the *x* axis
on the bottom and the *y* axis on the left, the labels are
below the *x* axis and above the *y* axis. On a 3-D plot
positive *x* and *y* go away from the corner at which the axes
meet so that both *x* and *y* labels are below the axes. It might
be helpful to think of the angles as being defined on an *x* axis
and then rotated to the appropriate axis. |