I am trying to use Neighborhood boundaries data(shape files) provide by Zillow.
files available at - http://www.zillow.com/howto/api/neighborhood-boundaries.htm
I am able to read the provided .dbf files but it just have information about state, county, city, name, and region ID.
can some one please guide me to get latitude longitudes or polygon information from this .dbf files or even from shape files.
also how to read the provided shape files?
Use the GetRegionChildren API to get the Lat/Long and other details corresponding to a regionId.
Related
Given a geoJSON representation of each US state (such as found here), along with user location coordinates (as available via CLLocationManager), what would be the best way to identify which state is the user in? What is the standard way to parse the geoJSON file, and simply identify which polygons contain the user location?
Let's say my location is in Indiana. I'm looking to create a function that parses the geoJSON representing the US, and identify that the user location only falls within the boundaries of Indiana coordinates.
Any suggestions/tips here is appreciated.
I've got a GeoJSON file of administrative borders i.e. state and county, and a CSV file with 12,500+ named GPS coordinates located within the geographic area.
My boss wants me to use the GeoJSON identify the county for each GPS location so I ended up with a CSV file (format) like;
LOCNAME, LOCLONG, LOCLAT, COUNTY, STATE
Is there any tool that can do this?
Thanks a bunch.
You may use QGIS to do this. You may import your geojson polygon file and import the csv containing coordinates as a point layer.
Follow the tutorial here: http://www.qgistutorials.com/en/docs/points_in_polygon.html
I am looking for shape files(polygons data) of all the districts in the world. I can find few files from different sources for districts of one country but I need one (updated) file that have all the districts in the world OR one reliable source from where I can get files may be one per country. Please help me find.
PS: shape files for countries and regions are easily available but not required in my case.
Geofabrik (http://download.geofabrik.de/) contains shapefiles for the whole world generated from OpenstreetMap data. These include administrative areas.
Natural Earth (see http://www.naturalearthdata.com/features/) has first-order administrative boundaries for the whole world.
I have geo data, that contain X field like: 1012532,749 and Y field like: 178774,7655. This data from the shapefile format, but I don`t know in what GEO standart this data is.
Maybe someone know, or can show me the way to find out, how translate this coords in GPS.
From your comment the situation is clear:
You got an invalid shape file:
The prj file states WGS84 coordinates in decimal degrees
which has range: (longitude(x) [-180-.0, 180.0], latitude(y): [-90.0, 90.0].
But the coordinates posted are not in valid range.
The prj definition does not fit to the rest of the shape files (your posted coordinate).
(This happens because the prj file is optional, and has probably the default settings of some other project)
There is little chance of knowing, without further knowlegde.
Simply ask the data provider which geographical datum (name) the coordinates are related to. Further you should claim, that the file is erorrnous and that they should provide a correct prj file (or remove the prj file, if the coordinates are not related to world coordinates)
IF you know the source, e.g the swiss "Landesvermessung" then you could think it is for example a "Swiss Grid CH1903+ / LV95" grid system. (This was an example, the coordinates are not in that Swiss grid)
But it does not make sense to reverse engineer that, just ask the data provider, or if appliable read the info where you have got that data from.
I need to find the 5 nearest zip code of a zip code.
For example, I have 33304, and I need to find the nearest ones, like 33309, 33308 ...
Is there a database or a web service somewhere that would help me with that?
I think I'm gonna have to build my own database in order to do that? I know how to do it, but in case it has already been done ...
what country? Maybe you want to checkout Geonames: http://www.geonames.org/
Especially: http://www.geonames.org/export/web-services.html#findNearbyPostalCodes
This answer is in response to the recent bounty requesting a location of US Zip Codes.
The United States Census Bureau has a list of zip codes (with latitude and longitude) on their web site.
The zip code tabulation areas is a CSV that contains (as described in the description of the file format), among other fields:
Column 1 GEOID Five digit ZIP Code Tabulation Area Census Code
...
Column 6 INTPTLAT Latitude (decimal degrees) First character is blank or "-" denoting North or South latitude respectively
Column 7 INTPTLONG Longitude (decimal degrees) First character is blank or "-" denoting East or West longitude respectively
I'd cross reference the above, with data from the Census Bureau's county business patterns CSV to get city, state and county names. This file format is described to contain (among other fields) (description is in the file you select to download):
ZIP C ZIP Code
NAME C ZIP Code Name
...
CITY C ZIP City Name
STABBR C ZIP State Abbreviation
CTY_NAME C ZIP County Name
Here is a free web service to do exactly what you need:
http://www.zipwise.com/webservices/
I tested geonames and did not find it good enough. Test areas near your zip code and you will not find all the zipcodew. These have good results but have not found any API yet
http://www.searchbug.com/tools/zip-radius.aspx
For the nearest ZIP Code, there are two approaches: find contiguous (adjoining) ZIP Codes and/or find the nearest ZIPs based on the distance from the center of one ZIP Code to the center of another, based on latitude and longitude.
To choose the contiguous ZIP approach, you will need ZIP Code Boundaries data. Alignstar makes one that we're very pleased with (we resell it), but ESRI and a couple of other companies have good products as well. My company, GreatData.com, developed a contiguous counties product and could develop a contiguous ZIP Codes product, but so far, nobody has been asking for it. This could be a data file or an API.
To find the nearest ZIP Codes based on centroids (latitude / longitude center points of the ZIP Code), you will need a ZIP Code Database with latitude / longitude data (we provide one, or go here for links to some free resources: //http://uszipcodes.com/free-zip-code-lookup.htm. If you just want an API and not the hassle of doing it yourself, let us know. We've started to develop similar APIs and will develop based on the demand.
One caveat of doing this by the centroids: we've seen in the past where if you have a large (or long), adjoining ZIP, the center of that ZIP could be farther away than another small ZIP Code, so your list of the 5 nearest could miss an adjoining ZIP.
PostgreSQL has new feature in 9.1 called "KNN". It is specifically for "Nearest Neighbor" distance searches, and from benchmarking and testing it it myself, it is very fast, and can be used for zipcodes. Here is a quick introduction to KNN.
You can also find a
thread about applying KNN to zipcodes, and a more recent follow-up.