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NSXCA Members Plotted By ZIP Code

Lud

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The cluster in CA near the NV border is probably an error, I'll look into it.. everything else looks right though.

nsxca-zip.gif
 
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Hey thats cool Lud, Is there a site you used to do that? I could use it for a project at work!!

Steve
 

Lud

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It is not from a site, it's a GIS application. I just plotted the ZIP codes of NSXCA members against a basemap of ZIP code locations.

Which after some more investigation may explain the blob in the Death Valley area near the CA/NV border. The ZIP codes in very lightly populated areas are big. I was only plotting ZIP codes, not city/state or lat/long. I think it just plotted them on the extreme edge of the area they were from. I'll check further to make sure though.

Re: south florida... look closely, they are there, they are just all RIGHT along the coast so they are harder to see because of the black line that defines the coast. They also make a line as opposed to a blob because they stretch from Palm Beach to Miami instead of being clustered around one spot like Orlando.

For reference, there are nearly 1000 ZIP codes plotted on that map. Most cluster in certain population centers and make lines or blobs.
 
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So in other words, if a zip code in (say) New York City is one pixel big, it will show on the map as one pixel, whether there is one NSX there or 50 of them. And if a zip code along the CA/NV border takes up a huge area and there's one NSX there, the entire area gets shaded.

Unfortunately, this means that the size of the shaded area does not necessarily represent the number of NSX owners in the area.

NOTE ADDED LATER - these statements are incorrect. See clarification by Lud below.

[This message has been edited by nsxtasy (edited 09 April 2001).]
 

Lud

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Sorry, I did not explain that clearly. It picks where within the polygon that geographically defines a ZIP code to plot the point.

If you have a large ZIP code area the points may be plotted on the far end of the ZIP code area from where the owners are actually located. In metro areas where ZIP code areas are small it doesn't make any difference at this scale, but in very sparsely populated areas it can make them look a bit off center. That is why ideally you also plot by address in addition to ZIP code, but I was just trying to get something up and running.

Anyway, it plots the same size point for all ZIP code "hits" regardless of where they are. If there are multiple hits on the same ZIP code it makes a bigger pixel. If there are a LOT of hits on the same ZIP code or lots of hits in ZIP codes that are very close together, you get a blob.
 
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