The newly inserted vertex becomes the vertex with the specified rank. Must be followed by a rank specifier. The newly inserted vertex appears immediately before the vertex with the specified rank. Must be followed by a rank specifier. The newly inserted vertex appears immediately following the vertex with the specified rank.
Several operations take marker and parent specifiers as arguments.
These are non-negative integers and denote the marker or parent with the specified index for this node. The tgraph node object supports programmatic extension through definition of new methods. See the method operation described below for the complete details. Such programmatically added methods are invoked through the call operation, also described below. This operation can be used to determine the kind of tgraph object stored in the Tcl variable node .