For nodes, the position indicates the center of the node. On output, the coordinates are in points.
pos can be used to set the initial position of a
node. By default, the coordinates are assumed to be in inches. However, the
-s command line flag can be used to specify different
units. As the output coordinates are in points, feeding the output of a graph
laid out by a Graphviz program into
fdp will almost always
-n command line flag is used with
is assumed the positions have been set by one of the layout programs, and are
therefore in points. Thus,
neato -n can accept input correctly without
-s flag and, in fact, ignores any such flag.