This task downloads OpenStreetMap® vectors based on the result of a query. OpenStreetMap data is available under Open Database Licence, www.openstreetmap.org/copyright.
Example
This example downloads and displays vectors for buildings, highways, and schools. Copy and paste the code into the IDL Editor and save it as DownloadOSMVectorsTaskExample.pro. Then compile and run the example.
PRO DownloadOSMVectorsTaskExample
COMPILE_OPT IDL2
e = ENVI()
File = Filepath('qb_boulder_msi', Subdir=['data'], $
Root_Dir=e.Root_Dir)
Raster = e.OpenRaster(File)
Task = ENVITask('DownloadOSMVectors')
Task.SUB_RECT=[-105.23, 39.98, -105.2, 40.01]
Task.FEATURE_NAMES=['Buildings','Highways and Roads']
Task.CUSTOM_NAMES=['amenity=school']
Task.VECTOR_TYPES=['Polygon','Polyline']
Task.Execute
View = e.GetView()
Layer = View.CreateLayer(Raster)
FOREACH vector, Task.OUTPUT_VECTOR DO BEGIN
e.Data.Add, vector
Layer2 = View.CreateLayer(vector)
ENDFOREACH
END
Syntax
Result = ENVITask('DownloadOSMVectors')
Input parameters (Set, Get): CUSTOM_NAMES, FEATURE_NAMES, MERGE_FEATURES, OUTPUT_DIRECTORY, SUB_RECT, VECTOR_TYPES
Output parameters (Get only): OUTPUT_VECTOR
Parameters marked as "Set" are those that you can set to specific values. You can also retrieve their current values any time. Parameters marked as "Get" are those whose values you can retrieve but not set.
Input Parameters
CUSTOM_NAMES (optional)
Specify a string array with custom feature names to query, using the format key=value. For example, the "power" feature (key) contains several sub-features (values) such as "plant", "cable", and "line." See https://wiki.openstreetmap.org/wiki/Map_Features for a list of keys and values. An example is power=tower. Not all sub-features will be available for a given feature, depending on the selected query region.
FEATURE_NAMES (optional)
Specify a string array with the standard feature names to query. The following are valid strings to use:
Aerial Transportation
Airport Infrastructure
Amenities
Barriers
Boundaries
Buildings
Crafts
Emergency
Geological
Highways and Roads
Historic
Land Use
Leisure
Man Made
Military
Natural
Offices
Places
Power
Public Transport
Railways
Routes
Shops
Sports
Tourism
Waterways
MERGE_FEATURES (required)
Set this parameter to true to merge features into a single vector file. For example, if you select three features to query, then all polygon vectors from these features will be merged into one vector file. The same applies for polyline and point vectors. The default value is false.
OUTPUT_DIRECTORY (optional)
Set this parameter to a string indicating the directory in which to save the resulting files. By default, the selected features will be downloaded and saved as shapefiles to the directory indicated in the ENVI Temporary Directory preference.
SUB_RECT (required)
Set this parameter to a four-element array expressing the spatial range for the query. The array is of the form: [minLongitude, minLatitude, maxLongitude, maxLatitude] in geographic coordinates.
VECTOR_TYPES (required)
Specify a string array with the vector types to download. Sometimes a single feature will contain elements of different vector types that must be stored in different files. The default behavior is to download all three vector types.
Polygon
Polyline
Point
Output Parameters
OUTPUT_VECTOR
This parameter contains an array of output ENVIVectors.
Methods
Execute
Parameter
ParameterNames
Properties
DESCRIPTION
DISPLAY_NAME
NAME
REVISION
TAGS
Version History
See Also
ENVITask, ENVIVector, ReprojectVector Task