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I'd like to make a nice "spiderweb" of a facility location problem, i.e. maximizing coverage with a given radius. This "radius" is just a straight line, Euclidian distance. As far as I can see, I don't need a "network" for that, but unfortunately all the solutions to find the closest facility to my demand points seem to be within the Network Analyst tool. So actually I'm looking for something more simple than that, there surely needs to be something?
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10-11-2017
07:48 AM
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Thanks Joe! Good point, I indeed mean precision rather than accuracy! Accuracy can be found with the Score attribute probably. In any way, I've checked the results, and they are accurate enough. I'll change the opening post, thanks again! However, what I'd like to know is is indeed the precision of the geocoded results. For example, if my data (i.e. address strings) only had a postal code, ArcGIS will give a Postal Addr_type after geocoding. Which is what it should do with the data provided, hence the accuracy is excellent. But the actual pinpointed location, is somewhere in within that postal code. So the precision depends on the size of the (polygon of the) postal code. For example, if the postal code is 100 square meters, then I know that the actual location must be somewhere within that area, and 100 square meters is possible deviation is good enough. However, if the particular postal code is a 100 square kilometers, the precision of actual location is arguably not good enough. Like I mentioned in the opening post, I was expecting Xmin and Xmax would give me the information of the possible deviation, but the results seem to give something different. So I think I misinterpret Xmin and Xmax, and that getting the precision of the results should be done differently.
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07-19-2017
04:38 AM
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I would say the following is a basic but crucial information, but I couldn't find good information about it. I'll explain what I have in mind, I might have some errors in my line of thought... I have geocoded my data with the World Geocoder. For further analysis, I'd like to use only the data that I consider accurate enough. For this, I thought that Addr_type ("The type of address that was geocoded. This attribute indicates to what kind of feature the address was matched") would be a good feature to analyse for precision. There you have types like PointAddress, StreetAddress and Postal, referring to a pin-pointed building as a location, a street segment, and a postal code respectively. For example, if Postal would have have an average radius (depending on the polygons of the postal codes) that is 500m, that would mean that the actual location can be 500m off. Then I would ignore all Postal data because I consider that not accurate enough. Or I could look per case of course, ignoring all individual data that is not accurate enough. For this analysis, I thought that Xmin, Xmax, Ymin, Ymax would contain the appropriate information. For Xmin, the link I mentioned before states: "The minimum x-coordinate for the display extent of a feature returned by the locator. The Xmin, Xmax, Ymin, and Ymax values can be combined to set the map extent for displaying a geocode result. The extent coordinates use the spatial reference of the locator (default)." I might be wrong, but this seems to have the correct information. So what I did is take the difference between the Xmax and Xmin (which is always the same as the difference between Ymax and Ymin) and analyse that. However, looking at those results, PointAddress has more or less the same range as StreetAddresses, which I would say is odd. However, what is much more weird is that Postal has the same range too (with almost no deviation in between results). But a postal code cannot be as accurate as a pinpointed building, right? What am I doing wrong? (By the way, for some better sense of "accuracy" I would like to have the "radius" or "range" in meters, for this I transform during post-processing the locations to UTM coordinates and then perform the same analysis by taking the difference between Xmax and Xmin. Would this be okay or are there better ways?)
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07-18-2017
02:30 PM
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