Pathfinder can generate analysis deliverables based on the data and scenarios in the project, providing information about the optimal location and route of the infrastructure.
Typically, these results are generated in sequence, since each one is needed to calculate the next one.
To run the generation processes and access the available results, use the Results section in the Pathfinder tab.
Calculate Resistance Map¶
The first result to be calculated is the Resistance Map (RM), a combination of all the layer resistances in the project using the selected MCDA model.
The RM can be used for optimal siting, since lowest values will represent areas where the total resistance or cost is smallest.
To generate the RM, click on the Generate Resistance Map button. The result will be added as a raster layer in ArcGIS Map and displayed on the map view.
Areas with Forbidden values (-999) are represented by No Data values in the output raster and they will look transparent. As with any raster layer in ArcGIS, the resistance map visualization can be changed using the ArcGIS symbology options, for instance, to use a preferred color ramp or change the minimum and maximum values to be displayed.
Calculate Corridor Map¶
The Corridor Map provides a summary of all possible paths from the Start to the End point with an accumulated resistance near the optimum value, so in addition to hinting where the optimum path will be located, it shows possible alternative routes whose resistance is not much worse.
To calculate the Corridor Map, go to the Results section in the Pathfinder tab and click on the Generate Corridor button.
A corridor display method, percentage or percentile, can be specified in the Scenario Settings pane.
If the Resistance Map has not been calculated when executing the Corridor Map calculation, this error message will appear:
After the calculation process is complete, the corridor map will be displayed in the Map View.
By default, darker colors mean lower resistance. As with the RM, the user can change the color palette using the ArcGIS symbology options.
You might get a failure message if the Start or End points of the project are inside a Forbidden area. In that case, you need to change the project or scenario points.
Once the Resistance Map and the Corridor Map are calculated, Pathfinder can find the optimal routes for a linear infrastructure going from the Start to the End points.
To run this calculation, click on the Generate Path button. The routing algorithm and other routing options can be modified in the Scenario Settings – Routing pane.
Instead of generating the Resistance Map, Corridor and Path(s) one by one, it is possible to generate them all in sequence. This can be done with Calculate All option in the Results section.
The different results will be added to the map as they are generated.
When project parameters (layers and their ring sizes) are changed, all the results should be recalculated to match these changes. If the Start or End points, layer resistances or scenario settings are changed, it is not necessary to recalculate the Resistance Map, only the Corridor Map and Paths.
When a process execution is in progress, it is shown in the Task section. The current add-in version only allows for one process at a time.
The calculated results are saved to a local disk folder, in the same location where the ArcGIS project is stored.
All the result files include a timestamp in their names, showing when they were generated. In this way, multiple results do not overwrite each other.
Disclaimer: the scenarios depicted in this manual do not represent actual customer projects or infrastructure proposals, and are presented for demonstration purposes only.
For more help, please contact Gilytics.