GEOTOOLS - Stata module to export data for GIS systems
Description
GEOTOOLS facilitates data export to shapefiles and GeoJSON files. It works fully within Stata (and hence works on any platform where Stata can be run) and does not have any dependencies (does not require e.g. ESRI ArcGIS or QGIS to be installed).
GEOTOOLS provides interactive dialogs, which can be of an advantage for novice users, and also can be called from the users' do and ado-files for massive or repetitive jobs.
The GEOTOOLS package contains additional utils for transforming the coordinates in Stata to bring them to the 'geography' format as required for the exporter to work.
Installation
To install geotools type literally the following in Stata's command prompt:
net from http://www.radyakin.org/stata/geotools/beta
Then click on the link for -geotools- in the Stata's viewer and click the -install- link.
Usage
Export in shapefile format
To export a file in shapefile format type the following in Stata's command line:
shapefile save geovar using "filename", type(shapefiletype)
For example:
clear input str100 building str100 name "-77.043346,38.899505;-77.041817,38.899505;-77.041817,38.898399;-77.043346,38.898399" "World Bank" "-77.043657,38.898460;-77.044757,38.898460;-77.044757,38.899468;-77.043657,38.899468" "International Monetary Fund" end shapefile save building using "C:\TEMP\NGOs", type(polygon)
Do not specify any file extension as multiple files will be created. Specify option replace if you want existing files to be replaced.
The type of the shapefile determines the type of the features that are stored in it and can be one of the following: point, multipoint, polyline, polygon.
Shapefiles (of either type) do not have any styling options.
Export in GeoJSON format
To export a file in GeoJSON format type the following in Stata's command line:
geojson save geovar using "filename", features("Polygon")
For example:
clear
input str100 building str100 name
"-77.043346,38.899505;-77.041817,38.899505;-77.041817,38.898399;-77.043346,38.898399" "World Bank"
"-77.043657,38.898460;-77.044757,38.898460;-77.044757,38.899468;-77.043657,38.899468" "International Monetary Fund"
end
geojson save building using "C:\TEMP\NGOs.geojson", features("Polygon")
Standard file extension is .geojson or .json, most tools do not require extension to be present in the file, but it is a convention to specify it. Specify option replace if you want existing files to be replaced.
The option features determines the type of the features being added to the output file and must be one of the following exact words: Point, MultiPoint, LineString, or Polygon.
The writer to GeoJSON format will save all the notes associated with the data in memory. It also saves all other variables (besides the geography) into the same file.
The following attributes can be utilized during writing to GeoJSON files:
- mcolor() - color of the markers in hex notation, e.g. #ff0000 for pure red;
- msize() - size of the markers, one of the following: small, medium, large;
- msymbol() - symbol to be used for the markers, which is a letter a..z, or a digit 0..9, or one of the symbols listed below;
- scolor() - color of lines in hex notation, e.g. #00ff00 for pure green;
- swidth() - width of lines (higher values = thicker lines);
- sopacity() - opacity of the lines 0..1; 0=transparent, 1=opaque;
- fcolor() - fill color in hex notation, e.g. #0000ff for pure blue;
- fopacity() - opacity of polygons' fill; 0=transparent, 1=opaque.
symbols list
Here is the full list of symbols that can be used for markers
aerialway airfield airport alcohol-shop america-football art-gallery bakery bank bar baseball basketball beer bicycle building bus cafe camera campsite car cemetery chemist cinema circle-stroked circle city clothing-store college commercial cricket cross dam danger dentist disability dog-park embassy emergency-telephone entrance farm fast-food ferry fire-station fuel garden gift golf grocery hairdresser harbor heart heliport hospital ice-cream industrial land-use laundry library lighthouse lodging logging london-underground marker-stroked marker minefield mobilephone monument museum music oil-well park2 park parking-garage parking pharmacy pitch place-of-worship playground police polling-place post prison rail-above rail-light rail-metro rail-underground rail religious-christian religious-jewish religious-muslim restaurant roadblock rocket school scooter shop skiing slaughterhouse soccer square-stroked square star-stroked star suitcase swimming telephone tennis theatre toilets town-hall town triangle-stroked triangle village warehouse waste-basket water wetland zoo
Each of these options may include either a constant or a variable name. In the former case the same value will be applied for the corresponding attribute of each feature being written, in the latter, different features may have different values of the same attribute. E.g. to create a simple choropleth map, specify fcolor(colorvar), where colorvar is a string variable with the desired color of each polygon feature.
Note that some options are different in the dialog and command line! In the dialog opacity is specified in percent, and hence can have values 0..100, while in the command line you should specify values from the range 0..1.
Important
A particular GIS system may or may not follow the recommended attributes. They should be meant as recommendations only. Additional instructions may be required to make the GIS system reflect the data accordingly.
A GIS visualizer may decide to visualize other attributes then listed above. For example, if you had a variable named title or name some visualizers may recognize it as a feature name and display on the map as a feature label.
Live maps
GeoJSON files constructed with these commands can serve as the basis for the live maps online. See the following examples (based on artificial data around Fortaleza, Brazil location):
Author
GEOTOOLS was written by Sergiy Radyakin.
To contact the author send email to: sradyakin/at/worldbank.org.