Да. Хотя для этого нет явного синтаксиса точек, вот как это делается почти всегда:
# just graph set-up
digraph new_graph {
ratio = "auto"
mincross = 2.0
# draw some nodes
"001" [shape=box, regular=1, style=filled, fillcolor="#FCD975"] ;
"017" [shape=circle , regular=1,style=filled,fillcolor="#9ACEEB" ] ;
"007" [shape=diamond , regular=1,style=filled,fillcolor="#FCD975" ] ;
# the key line--creating tiny node w/ no label, no color
# i use this style because it mimics the 'midpoint' style used in Omnigraffle et al.
"LN01" [shape=diamond,style=filled,label="",height=.1,width=.1] ;
# draw the edges
"001" -> "LN01" [dir=none,weight=1] ;
"007" -> "LN01" [dir=none,weight=1] ;
"LN01" -> "017" [dir=none, weight=2] ;
}
альтернативный текст http://img121.imageshack.us/img121/2547/dotgvziv.png