Algorithms For Dummies

  Understanding Graph Basics 

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Medical professionals also use subgraphs to understand the flow of blood or other 

liquids between organs in the body. The organs are the nodes and the blood ves-

sels are the edges. In fact, many of these graphs are weighted — it’s essential to 

know how much blood is flowing, not just that it’s flowing.

Complex graphs can also hide patterns that you need to know about. For example, 

the same cycle can appear in multiple parts of the graph, or you might see the 

same cycle within different graphs. By creating a subgraph from the cycle, you can 

easily perform comparisons within the same graph or between graphs to see how 

they compare. For example, a biologist might want to compare the cycle of muta-

tion for one animal against the cycle of mutation for another animal. To make this 

comparison, the biologist would need to create the representation as a subgraph 

of the processes for the entire animal. (You can see an interesting view of this 

particular use of graphs at 

http://www.sciencedirect.com/science/article/

pii/S1359027896000569

.). The graph appears near the beginning of the article as 

Figure 1.