The OPTGRAPH Procedure

REACH Statement

REACH < options >;

The REACH statement invokes an algorithm that calculates the reach (ego) network on an input graph.

The reach network is described in the section Reach (Ego) Network.

You can specify the following options in the REACH statement:

BY_CLUSTER

decomposes the calculations by cluster (subgraph). If this option is specified, PROC OPTGRAPH looks for a definition of the clusters in the input data set specified in the DATA_NODES= option in the PROC OPTGRAPH statement. If BY_CLUSTER is specified, the reach network links output (specified in the OUT_LINKS= option) cannot be generated.

DIGRAPH

calculates the directed reach counts when computing the reach networks and includes the directed counts in the resulting output data set that is specified in the OUT_COUNTS= option. This option is ignored unless you specify MAXREACH=1 in the REACH statement.

EACH_SOURCE

treats each node as a source and calculates a reach network from each one.

IGNORE_SELF

ignores the source nodes in the reach network node counts.

MAXREACH=number

specifies the maximum number of links to allow from each source node in a reach network. By default, MAXREACH=1.

LOGFREQTIME=number

displays iteration logs for the reach algorithm every number seconds. When PROC OPTGRAPH runs the reach algorithm, it displays the number of source networks that have completed. When you also specify the BY_CLUSTER option in the REACH statement, PROC OPTGRAPH displays the number of subgraphs that have completed. The value of number can be any integer greater than or equal to 1; the default is 5. Setting this value too low can hurt performance on large-scale graphs.

LOGLEVEL=number

controls the amount of information that is displayed in the SAS log. Table 1.36 describes the valid values for this option.

Table 1.36: Values for LOGLEVEL= Option

number	string	Description
0	NONE	Turns off all algorithm-related messages in the SAS log
1	BASIC	Displays a basic summary of the algorithmic processing
2	MODERATE	Displays a summary of the algorithmic processing
3	AGGRESSIVE	Displays a detailed summary of the algorithmic processing

The default is the value that is specified in the LOGLEVEL= option in the PROC OPTGRAPH statement (or BASIC if that option is not specified).

OUT_COUNTS=SAS-data-set

specifies the output data set to contain the node counts in each reach network.

OUT_COUNTS1=SAS-data-set

specifies the output data set to contain the node counts in each reach network for the special case of calculating only counts that have limit 1 and 2. This data set holds the counts with MAXREACH=1. This option works only when the EACH_SOURCE and BY_CLUSTER options are specified.

OUT_COUNTS2=SAS-data-set

specifies the output data set to contain the node counts in each reach network for the special case of calculating only counts that have limit 1 and 2. This data set holds the counts with MAXREACH=2. This option works only when the EACH_SOURCE and BY_CLUSTER options are specified.

OUT_LINKS=SAS-data-set

specifies the output data set to contain the links in each reach network.

OUT_NODES=SAS-data-set

specifies the output data set to contain the nodes in each reach network.