Field Reports tell how instructors have used AVs in their teaching.

Using graph visualization with code.

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chelwig
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Instructor(s): 
Catherine Helwig
Location: 
Villanova
Course: 
Algorithms & Data Structures III
Term / Date: 
Fall 2008

This visualization is one of five that was used as a mini-tutorial in a Data Structures III class.  Last year was the first time it was used and students were encouraged to use it as basis for creating visualizations of their own.  Time was limited, so this year I allocating more time to help the students devise their own animations.

On the introductory page, the definition of the algorithm is presented and then its characteristics are listed. In the animation, two different views of the algorithm are presented  to illustrate the execution of Dijkstra's algorithm.

The animation includes a demo of how the algorithm works with related code and then students can create their graphs, weights and edges and run the algorithm with related code appearing. The instructions given are below

"Then select either step or run to execute the algorithm. Note that it starts by assigning a weight of infinity to all nodes, and then selecting a source and assigning a weight of zero to it. As nodes are added to the set for which

shortest paths are known, their colour is changed to red. When a node is selected, the weights of its neighbours are relaxed .. nodes turn green and flash as they are being relaxed. Once all nodes are relaxed, their predecessors

are updated, arcs are turned green when this happens. The cycle of selection, weight relaxation and predecessor update repeats itself until all the shortest path to all nodes has been found."

  

There are four other visualization on this site that can be used similarly.

I found that the students were interested but that I needed to spend more class time explaining visualization development.

shaffer
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Re: Using graph visualization with code.

Is the focus of your exercise to get students to develop an AV (and you show them an example)? Or is it to get students to use an AV to learn this algorithm?

 

chelwig
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Re: Using graph visualization with code.

In reply to your question:

I intended at first to just use the visualization to illustrate the algorithms but now I am focusing on getting them to do  visualizations in my advanced (Data Structures III ) class.  I am giving an open project this term and will go over

each of the visualizations and explain what each will require in terms of expertise and time.  Mostly, it will give them ideas on how to develop their own animations.  The biggest hurdle with an open project is getting them started!

shaffer
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Re: Using graph visualization with code.

Please let us know how it works out!