Skip to contents

From a QuadKey to a Simple Features data.frame and other conversions

Functions to convert a QuadKey to a sf POINT data.frame or sf POLYGON data.frame. Additionally, all the R functions described in the official documentation to convert QuadKeys to and from tiles, pixels and geographic coordinates are available.

quadkey_to_polygon()
Convert a QuadKey into a square polygon
quadkey_to_latlong()
Convert a string of Quadkey numbers to lat/long coordinates
quadkey_to_tileXY()
Convert a QuadKey into tile XY coordinates.
tileXY_to_pixelXY()
Convert tile XY coordinates into pixel XY coordinates
pixelXY_to_latlong()
Convert pixel XY coordinatess into lat/long coordinates.
latlong_to_quadkey()
Convert latitude/longitude coordinates into QuadKeys
latlong_to_pixelXY()
Convert lat/long coordinates to pixel XY coordinates
pixelXY_to_tileXY()
Convert pixel XY coordinates into tile XY coordinates
tileXY_to_quadkey()
Convert tile XY coordinates into a QuadKey.
mapsize()
Map size in pixels
mapscale()
Map scale (1 : N)
ground_res()
Ground resolution at a specified latitude and zoom level

Generating a Raster Image from Quadkey-Identified Data

Complete a grid of QuadKeys within a specified area and zoom level, and create a stars raster. You can also directly convert QuadKeys in a data.frame column into an sf POLYGON data.frame.

add_regular_polygon_grid()
Add the rows needed to complete a regular QuadKey polygon grid derived from the bounding box of the quadkey column of a data.frame.
create_stars_raster()
Create a stars raster
quadkey_df_to_polygon()
Convert data.frame with quadkey column to a sf POLYGON data.frame
create_qk_grid()
Create grid of QuadKeys for a particular zoom or level of detail.
get_qk_coord()
Get lat/long coordinates from the QuadKey
regular_qk_grid()
Convert a incomplete QuadKey sf POINT data.frame into a regular grid.
grid_to_polygon()
Convert a grid of QuadKeys to square polygons

Converting Facebook Mobility QuadKey-identified Datasets into Raster Files

Convert Facebook mobility data .csv files into .tif files by day and hour reported.

read_fb_mobility_files()
Read all the .csv files in a folder and format the data.
format_fb_data()
Format the Facebook mobility data
missing_combinations()
Detect dates and hours missing in filenames
get_regular_polygon_grid()
Get regular QuadKey polygon grid derived from the bounding box of the quadkey column of a data.frame.
polygon_to_raster()
Create and save raster images for different dates and times
apply_weekly_lag()
Apply a 7 day lag to the variable n_crisis

QuadKey Visualization App

Introduce a QuadKey visualization application enabling users to validate function outcomes.

qkmap_app()
Launch the Shiny App