Business Context
A city's water department is analyzing its pipe network from raw, potentially messy data. The network contains separate, unconnected water systems (e.g., for potable water and reclaimed water). The data may also contain errors like self-loops (a pipe connecting a junction to itself) and multi-links (multiple pipes recorded for the same two junctions).
About the Set : optNetwork
Network analysis and graph algorithms.
Discover all actions of optNetwork Data Preparation
Creation of a dataset with two disconnected components, a self-link, and a multi-link to simulate imperfect data.
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| 1 | DATA mycas.WaterPipes; |
| 2 | INPUT from $ to $; |
| 3 | DATALINES; |
| 4 | J1 J2 |
| 5 | J2 J3 |
| 6 | J3 J1 /* Component 1: A triangle */ |
| 7 | J4 J5 /* Component 2: A simple link */ |
| 8 | J6 J6 /* Self-link */ |
| 9 | J2 J3 /* Multi-link */ |
| 10 | ; |
| 11 | RUN; |
Étapes de réalisation
1
Run the analysis with default settings, which should process self-links and multi-links.
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| 1 | PROC CAS; |
| 2 | ACTION optNetwork.biconnectedComponents / |
| 3 | links={name='WaterPipes'} |
| 4 | outLinks={name='mycas.Pipes_Default', replace=true} |
| 5 | outNodes={name='mycas.Junctions_Default', replace=true}; |
| 6 | RUN; |
| 7 | QUIT; |
2
Run the analysis again, but this time explicitly ignoring self-links and multi-links to see how it affects the results.
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| 1 | PROC CAS; |
| 2 | ACTION optNetwork.biconnectedComponents / |
| 3 | links={name='WaterPipes'} |
| 4 | selfLinks=FALSE |
| 5 | multiLinks=FALSE |
| 6 | outLinks={name='mycas.Pipes_Filtered', replace=true} |
| 7 | outNodes={name='mycas.Junctions_Filtered', replace=true}; |
| 8 | RUN; |
| 9 | QUIT; |
3
Compare the component assignments in both output link tables.
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| 1 | PROC CAS; |
| 2 | TABLE.fetch / TABLE={name='Pipes_Default'}; |
| 3 | TABLE.fetch / TABLE={name='Pipes_Filtered'}; |
| 4 | RUN; |
| 5 | QUIT; |
Expected Result
The action should correctly identify two main biconnected components corresponding to the two disconnected water systems. In the first run, the self-link on J6 will form its own biconnected component. In the second run, this J6 component will disappear. The multi-link between J2 and J3 will be treated as a single link in the second run. This demonstrates the action's ability to handle disconnected graphs and validates the behavior of the `selfLinks` and `multiLinks` parameters.