The CONCOMP statement invokes an algorithm that finds the connected components of the input graph. Connected components are described in the section Connected Components.
You can specify the following options in the CONCOMP statement:
-
ALGORITHM=DFS | UNION_FIND
specifies the algorithm to use for calculating connected components.
Table 24: Values for the ALGORITHM= Option
| Option Value | Description |
|---|
| DFS | Uses the depth-first search algorithm for connected components. You cannot specify this value when you specify GRAPH_INTERNAL_FORMAT=THIN in the PROC OPTGRAPH statement. |
| UNION_FIND | Uses the union-find algorithm for connected components. You can specify this value with either the THIN or FULL value for the GRAPH_INTERNAL_FORMAT= option in the PROC OPTGRAPH statement. This value can be faster than DFS when used with GRAPH_INTERNAL_FORMAT=THIN. However, you can use it only with undirected graphs. |
By default, ALGORITHM=UNION_FIND for undirected graphs, and ALGORITHM=DFS for directed graphs.
-
LOGLEVEL=number | string
controls the amount of information that is displayed in the SAS log. Table 25 describes the valid values for this option.
Table 25: 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).