The NETDRAW Procedure

Variables in the Network Data Set

The NETDRAW procedure expects all the network information to be contained in the Network input data set named by the DATA= option. The network information is contained in the ACTIVITY and SUCCESSOR variables. In addition, the procedure uses default variable names in the Network data set for specific purposes. For example, the _X_ and _Y_ variables, if they are present in the Network data set, represent the coordinates of the nodes, the _SEQ_ variable indexes the turning points of each arc of the network, and so on.

In addition to the network precedence information, the Network data set may also contain other variables that can be used to change the default layout of the network. For example, the nodes of the network can be aligned in the horizontal direction using the ALIGN= specification, or they can be divided into horizontal bands (or zones) using a ZONE variable.

Table 7.15 lists all of the variables associated with the Network data set and their interpretations by the NETDRAW procedure. Note that all the variables are identified to the procedure in the ACTNET statement. Some of the variables use default names that are recognized by the procedure to denote specific information, as explained previously. The table indicates if the variable is default or needs to be identified in the ACTNET statement.

Table 7.15: Network Data Set and Associated Variables

Statement	Variable Name	Interpretation
ACTNET	ACTIVITY	Activity or node name
	ALIGN	Align variable for time-scaled network
	DURATION	Duration of activity
	ID	Additional variables to be displayed
	PATTERN	Pattern number
	SUCCESSOR	Immediate successor
	WEB	HTML page corresponding to activity
	ZONE	Zone variable for dividing network
Default	A_FINISH	default ID variable
Variable	A_START	default ID variable
Names	E_FINISH	default ID variable
	E_START	default ID variable
	F_FLOAT	default ID variable
	L_FINISH	default ID variable
	L_START	default ID variable
	S_FINISH	default ID variable
	S_START	default ID variable
	T_FLOAT	default ID variable
	_FROM_	supersedes ACTIVITY= specification
	_PATTERN	supersedes PATTERN= specification
	_SEQ_	index of turning point in arc
	_TO_	supersedes SUCCESSOR= specification
	_X_	coordinate of node or arc turning point
	_Y_	coordinate of node or arc turning point