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 1.24: 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 1.25 describes the valid values for this option.
Table 1.25: 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).