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I have a simple workflow trying to find a shortest path between 2 points. I am using a Cook County (Chicago) road network and a Creator to enter from and to points. In spite of different snap distances I keep getting an error "No shortest path found from...".

My workflow is attached and the network file is from:

https://catalog.data.gov/dataset/tiger-line-shapefile-2013-county-cook-county-il-all-roads-county-based-shapefile

TIA,

George

I see you created the line with coordinate system LL84.

Is the Shape file you are using in the same coordinate system?

If the Shape file does not have coordinate system information, you might want to use the CoordinateSystemSetter transformer to assign a coordinate system.

I would check the data sources using two inspector transformers to see if they match (location).

Hi @gjgorczynski, the ShortestPathFinder requires the network lines are noded properly, but the download data seems not to be so. Consider using the TopologyBuilder (Assume Clean Data: No) to make a network consisting of lines connecting each other at their end nodes.

I totally agree with @takashi it's the first thing that I would check...

Hi @gjgorczynski, the ShortestPathFinder requires the network lines are noded properly, but the download data seems not to be so. Consider using the TopologyBuilder (Assume Clean Data: No) to make a network consisting of lines connecting each other at their end nodes.

Perfect! TopologyBuilder fixed it. Thank you @takashi. How did you know that the lines were not noded properly?

 

I see you created the line with coordinate system LL84.

Is the Shape file you are using in the same coordinate system?

If the Shape file does not have coordinate system information, you might want to use the CoordinateSystemSetter transformer to assign a coordinate system.

I would check the data sources using two inspector transformers to see if they match (location).

Thanks for the suggestion @erik_jan.

 

Perfect! TopologyBuilder fixed it. Thank you @takashi. How did you know that the lines were not noded properly?

 

Just had a look at the data with FME Data Inspector ;-)

 

Just had a look at the data with FME Data Inspector ;-)

 

I think I know what you mean, there should be nodes at all intersections. Thanks again, I'm totally new to FME.
I think I know what you mean, there should be nodes at all intersections. Thanks again, I'm totally new to FME.
That is spot on, there has to be a node at all the allowed intersections for the ShortestPathFinder to consider them.
I think I know what you mean, there should be nodes at all intersections. Thanks again, I'm totally new to FME.
I would strongly advise reading on the transformer used to understand its working and needed input. Each transformer has a Help button that will open up the help page where this information can be found.

 

 

"Input line features must be a topologically noded network with features connecting at line ends only. That is, all features must be split at junctions."

 

 

Hope this helps and happy FME'ing!

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