• To place tick labels perpendicular to an axis (rather than parallel to it), use parallel#=n, where # is 1, 2, or 3.
• .

• To control the tick selection manually, use n#tic=, o#=num, and d#num=.
• To control the label format, use format#= (the argument is a printf-style string)

The following example is provided in rsf/rsf/sfgraph: