Question

Getting seperate isoc-rasters from multiple points

M
Badge +3

I have a set of points (>100) and I want to calculate a cost raster along a network fpor each point. For 1 point I can do this by:

point > netyworkcostcalculator>surfacemodeller.

 

However when I use multiple points the networkcostcalculator only outputs disconnected features (also when using 'group by' point ID). But even if it would have an output, the output does not contain an pointID attribute, so I can not use the group by option in the surface modeller.

 

Is there an easy way to calculate a cost raster for more then 1 point?

 

 

2 replies

ctredinnick
Rank
Userlevel 3
Badge +16

The NetworkCostCalculator can only trace for one point at a time. It's computationally intensive to do this with a lot of points, but if you duplicate your network once for each source point (Aggregate source points together, making a list of their IDs, FeatureMerger that list onto the network, and then ListExploder so you get a copy of the network each with the ID of the point it's for), then the Group By on the NetworkCostCalculator will trace each point separately.

This creates another issue that you then need to collapse that result set into one. This could be done by chopping the network into points, extract the Z value, intersect points where they touch (adding list of the Z values), and only keep the point with the lowest Z value. Then you can create the DEM from that set of network points.

M
Badge +3

The NetworkCostCalculator can only trace for one point at a time. It's computationally intensive to do this with a lot of points, but if you duplicate your network once for each source point (Aggregate source points together, making a list of their IDs, FeatureMerger that list onto the network, and then ListExploder so you get a copy of the network each with the ID of the point it's for), then the Group By on the NetworkCostCalculator will trace each point separately.

This creates another issue that you then need to collapse that result set into one. This could be done by chopping the network into points, extract the Z value, intersect points where they touch (adding list of the Z values), and only keep the point with the lowest Z value. Then you can create the DEM from that set of network points.

I was too focussed on creating a loop to do it point by point. The first part of your post was enough for me. I wanted to generate a single raster per point so I could add a weighing factor to each raster. Thank you very much!

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