Hello all,
I have a street network and a point dataset (of schools).
How do I calculate those streets that represent a 3.5km driven distance from each school?
I can calculate one school at a time, if that is necessary
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+59- Celebrity
- 3700 replies
You can try the NetworkCostCalculator, in order to speed things up you may want to only apply that to objects within a 3.5 km buffer of any given school.
+14- Contributor
- 116 replies
I have something that sort of works
NetworkCostCalculator
MeasureExtractor
ListIndexer
AttributeRangeFilter
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But the result is not ideal.
For MeasureExtractor I chose Type "Whole Line" which gives me a measure for the whole line, but I suspect I may be better off with Type "Individual Vertex" which I think will give me the driven distance for each vertex of each line.
I was really hoping for a transformer where I specify a driven distance and the output is the road network inside that driven distance
+59- Celebrity
- 3700 replies
I have something that sort of works
NetworkCostCalculator
MeasureExtractor
ListIndexer
AttributeRangeFilter
Â
But the result is not ideal.
For MeasureExtractor I chose Type "Whole Line" which gives me a measure for the whole line, but I suspect I may be better off with Type "Individual Vertex" which I think will give me the driven distance for each vertex of each line.
I was really hoping for a transformer where I specify a driven distance and the output is the road network inside that driven distance
Yes, individual vertex would give you a bit more detail. I did something similar a few years ago for drivetime polygons (pretty much the same process), but found it a very "expensive" process. A 5-minute drivetime polygon in an urban area took about 10-15 minutes to calculate.
+25- Enthusiast
- 109 replies
Have you looked at this article? https://knowledge.safe.com/articles/30048/creating-time-and-distance-isolines-using-the-netw.html
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If you're only interested in the road links within 3.5 km and not the areas, you don't even have to create the isolines.+14- Contributor
- 116 replies
Have you looked at this article? https://knowledge.safe.com/articles/30048/creating-time-and-distance-isolines-using-the-netw.html
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If you're only interested in the road links within 3.5 km and not the areas, you don't even have to create the isolines.Thanks, this helps me make progress.
I am successfully creating contour lines at the interval I need.
But, I really want polygons, so that I can detect if a point is within or without the 3.5km driven distance.
How do I convert the contour lines into polygons?
+14- Contributor
- 116 replies
More progress. I use;
AttributeFilter to only keep the contour intervals I want (keep 3.5km, discard 7km)
LineJoiner to join the contour lines end-to-end into one line
GeometryCoercer to convert the line into a polygon
Which is great!
Except that, within the polygon is a spot that should be a donut hole. But there is no hole. I have a second line outlining the hole and that is its own polygon.
How do I generate a polygon that has a proper donut hole?
+14- Contributor
- 116 replies
Okay, so the trick to building polygons with donut holes is to use AreaBulder, not GeometeryCoercer
+14- Contributor
- 116 replies
Specifically, AreaBuilder with;
CreateDonuts ticked (on) and
Drop Holes = Yes
this creates polygons with donut holes (but the holes are not separate polygon features)
+14- Contributor
- 116 replies
Is there a transformer that can split a line by measure (or elevation)?
And another transformer that can filter features by measure (or elevation)?