ShortestPathFinder
From fmepedia
ShortestPathFinder is a Workbench Transformer.
| Table of contents |
Description
The ShortestPathFinder finds the shortest path from a source node to a destination node - including the ability to apply a weighting by length or by attribute (PR#19448)
The start/end point can either match a coordinate on the network, or be snapped to the nearest network node using a tolerance parameter.
Example
The attached workspace shows an example use of the ShortestPathFinder transformer.
Scenario
Here is a road network for the city of Interopolis. We have a defined start and end point and wish to find the shortest path from one to the other.
The source data is the RoadLine.mif/mid dataset found in the FME Sample Dataset (http://www.safe.com/support/onlinelearning/fmesampledata.php).
Workspace Screenshots
Above The source data is added and the start/end points defined using Creator transformers.
Output
Above The output is to the Visualizer - the road network as a base, plus the route defined by the transformer
Enhancements
This example could be enhanced fairly easily with any of the following:
- If the road dataset contains info on speed limits then you could use some parameters like below to take speed into account when defining routes.
- The user could define their own coordinates....
- It would be fairly straightforward to have the user enter the coordinates with a parameter, rather than defining them with Creators.
- It would be a little more complex to have the user enter addresses, geocode them with a web service, and use those coordinates.
- It would be harder (though not impossible) to allow the user to select the start and end point on a graphic map display.
Above Weighting the route by road speed limits. Since this screenshot extra settings have been added for snapping the start and end points.
