isochrone_png: Issue a walkalytics isochrone query
Description
isochrone_png calls the walkalytics isochrone API which calculates the walking isochrone for a source location
and returns a repsonse object that contains a base64-encoded raster as PNG file with classified isochrones.
x-coordinate of the source location (coordinate system is WGS/84 Pseudo Mercator).
y
y-coordinate of the source location (coordinate system is WGS/84 Pseudo Mercator).
epsg
EPSG code for coordinate system of the x- and y-coordinate.
max_min
integer. Maximum number of minutes for the isochrone.
break_values
a vector of break values (walking time in minutes) for the classification of the PNG result.
key
your walkalytics subscription key which provides access to the API.
Value
The response object from the request. Use save_png to save the base64-encoded
PNG to file.
Details
To get an API key, you need to register at https://dev.walkalytics.com/signin.
With the free starter account, you can make up to 100 calls a week to the API.