Help for package quadkeyr

Title:

Generate Raster Images from QuadKey-Identified Datasets

Version:

0.1.0

Description:

A set of functions of increasing complexity allows users to (1) convert QuadKey-identified datasets, based on 'Microsoft's Bing Maps Tile System', into Simple Features data frames, (2) transform Simple Features data frames into rasters, and (3) process multiple 'Meta' ('Facebook') QuadKey-identified human mobility files directly into raster files. For more details, see D’Andrea et al. (2024) <doi:10.21105/joss.06500>.

License:

MIT + file LICENSE

URL:

https://docs.ropensci.org/quadkeyr/, https://github.com/ropensci/quadkeyr

BugReports:

https://github.com/ropensci/quadkeyr/issues

Encoding:

UTF-8

RoxygenNote:

7.3.2

Suggests:

bslib (≥ 0.6.1), DT (≥ 0.31), ggplot2 (≥ 3.4.4), knitr, leaflet (≥ 2.2.1), magick (≥ 2.8.5), rmarkdown, rnaturalearth (≥ 1.0.0), shinytest2 (≥ 0.3.2), testthat (≥ 3.1.10), tidyr (≥ 1.3.0), viridis (≥ 0.6.4), withr

VignetteBuilder:

knitr

Depends:

R (≥ 4.1.0)

LazyData:

true

Imports:

dplyr (≥ 1.1.2), lubridate (≥ 1.9.2), purrr (≥ 1.0.1), readr (≥ 2.1.4), rlang (≥ 1.1.2), sf (≥ 1.0.14), shiny (≥ 1.7.4), stars (≥ 0.6.2)

NeedsCompilation:

Packaged:

2025-03-24 00:53:18 UTC; runner

Author:

Florencia D'Andrea

[aut, cre], Pilar Fernandez

[aut], Maria Paula Caldas

[rev] (Maria Paula Caldas reviewed the package (v. 0.0.0.9000) for rOpenSci, see https://github.com/ropensci/software-review/issues/619), Vincent van Hees

[rev] (Vincent van Hees reviewed the package (v. 0.0.0.9000) for rOpenSci, see https://github.com/ropensci/software-review/issues/619), Andrew Pulsipher

[ctb], CDC's Center for Forecasting and Outbreak Analytics [fnd] (This project was made possible by cooperative agreement CDC-RFA-FT-23-0069 (grant # NU38FT000009-01-00) from the CDC's Center for Forecasting and Outbreak Analytics. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention.), MIDAS-NIH COVID-19 urgent grant program [fnd], Paul G. Allen School for Global Health, Washington State University [cph]

Maintainer:

Florencia D'Andrea <florencia.dandrea@gmail.com>

Repository:

CRAN

Date/Publication:

2025-03-24 15:00:02 UTC

quadkeyr: Generate Raster Images from QuadKey-Identified Datasets

Description

Author(s)

Maintainer: Florencia D'Andrea florencia.dandrea@gmail.com (ORCID)

Authors:

Pilar Fernandez pilar.fernandez@wsu.edu (ORCID)

Other contributors:

Maria Paula Caldas (ORCID) (Maria Paula Caldas reviewed the package (v. 0.0.0.9000) for rOpenSci, see https://github.com/ropensci/software-review/issues/619) [reviewer]
Vincent van Hees (ORCID) (Vincent van Hees reviewed the package (v. 0.0.0.9000) for rOpenSci, see https://github.com/ropensci/software-review/issues/619) [reviewer]
Andrew Pulsipher (ORCID) [contributor]
CDC's Center for Forecasting and Outbreak Analytics (This project was made possible by cooperative agreement CDC-RFA-FT-23-0069 (grant # NU38FT000009-01-00) from the CDC's Center for Forecasting and Outbreak Analytics. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention.) [funder]
MIDAS-NIH COVID-19 urgent grant program [funder]
Paul G. Allen School for Global Health, Washington State University [copyright holder]

Add the rows needed to complete a regular QuadKey polygon grid derived from the bounding box of the `quadkey` column of a data.frame.

Description

This function estimates the bounding box of the quadkeys given in the quadkey column and adds rows to complete the quadkeys and the geometry needed to create a regular grid. All other columns for the introduced QuadKeys will be filled with NAs.

For a detailed explanation on how to use this and other similar quadkeyr functions, read the the vignette: https://docs.ropensci.org/quadkeyr/articles/quadkey_identified_data_to_raster.html

Usage

add_regular_polygon_grid(data)

Arguments

data

A data.frame with a quadkey column.

Value

A list with three elements:

data A sf POLYGON data.frame with all the QuadKeys within the bounding box of the ones provided in the quadkey column of the input dataset, and the rest of the original variables. The columns quadkey and geometry are returned for all the grid, The values of the newly added QuadKeys will be NA for the rest of the variables.
num_rows The number of columns of the regular grid.
num_cols The number of rows of the regular grid.

Examples


# Read the file with the data
path <- paste0(
  system.file("extdata", package = "quadkeyr"),
  "/cityA_2020_04_15_0000.csv"
)
data <- read.csv(path)
data <- format_fb_data(data)

add_regular_polygon_grid(data = data)

Apply a 7 day lag to the variable `n_crisis`

Description

Applying a week lag to the data will create raster images showing the mobility a week before the date of interest. This function works only for QuadKeys reported without NAs for n_crisis and percent_change variables .

Usage

apply_weekly_lag(data)

Arguments

data

A data.frame with the columns quadkey, day, hour and n_crisis.

Value

A data.frame with the extra columns n_crisis_lag_7 and percent_change_7.

n_crisis_lag_7, is the same variable defined as n_crisis in the Facebook mobility data.frame with a 7 day lag applied.
percent_change_7 is the difference between the n_crisis value between weeks expressed as percentage.

Examples


files <- read_fb_mobility_files(
  path_to_csvs = paste0(system.file("extdata",
    package = "quadkeyr"
  ), "/"),
  colnames = c(
    "lat",
    "lon",
    "quadkey",
    "date_time",
    "n_crisis",
    "percent_change"
  ),
  coltypes = list(
    lat = "d",
    lon = "d",
    quadkey = "c",
    date_time = "T",
    n_crisis = "c",
    percent_change = "c"
  )
)

apply_weekly_lag(data = files)

Create grid of QuadKeys for a particular zoom or level of detail.

Description

Generates a grid comprising all the QuadKeys within the area defined by the maximum and minimum coordinates of latitude and longitude along with a specified zoom level.

Usage

create_qk_grid(xmin, xmax, ymin, ymax, zoom)

Arguments

xmin

Minimum value in the x axis (longitude)

xmax

Maximum value in the y axis (latitude)

ymin

Minimum value in the x axis (longitude)

ymax

Maximum value in the Y axis (latitude)

zoom

Zoom or level of detail, from 1 (lowest detail) to 23 (highest detail).

Value

A list returning the QuadKeys as a data.frame (data), the number of rows (num_rows) and columns (num_cols) of the grid.

Examples


grid <- create_qk_grid(
  xmin = -59,
  xmax = -57,
  ymin = -35,
  ymax = -34,
  zoom = 12
)

Create a `stars` raster

Description

The use of a template enables the creation of an accurate raster, even in the presence of NAs.

Usage

create_stars_raster(template, nx, ny, data, var)

Arguments

template

A sf POLYGON data.frame to use as template. Check stars::st_as_stars() documentation for more details.

nx

Integer; number of cells in x direction.

ny

Integer; number of cells in y direction.

data

A sf POLYGON data.frame with the variable we want to represent in the raster.

var

The column name of the variable to plot.

Value

A stars object.

Examples


# Basic workflow
# Read the data
path <- paste0(
  system.file("extdata", package = "quadkeyr"),
  "/cityA_2020_04_15_0000.csv"
)
data <- read.csv(path)
data <- format_fb_data(data)

complete_polygon_grid <- add_regular_polygon_grid(data = data)

stars_object <- create_stars_raster(
  data = complete_polygon_grid$data,
  template = complete_polygon_grid$data,
  var = "percent_change",
  nx = complete_polygon_grid$num_cols,
  ny = complete_polygon_grid$num_rows
)
stars_object

# Other workflow
grid <- create_qk_grid(
  xmin = -59,
  xmax = -57,
  ymin = -35,
  ymax = -34,
  zoom = 12
)

grid_coords <- get_qk_coord(data = grid$data)

polygrid <- grid_to_polygon(grid_coords)

data("data_provided")
data_raster <- polygrid |>
  dplyr::inner_join(data_provided,
    by = c("quadkey")
  )

raster <- create_stars_raster(
  template = data_raster,
  nx = grid$num_cols,
  ny = grid$num_rows,
  data = data_raster,
  var = "variable"
)

QuadKey-identified Dataset

Description

A data.frame simulating a QuadKey-identified dataset.

Usage

data_provided

Format

`data_provided`

A data.frame with 360 rows and 2 columns:

quadkey: QuadKey as a string
variable: Numeric variable

Format the Facebook mobility data

Description

This function removes unnecessary characters such as ⁠\\N⁠ and ensures that the format of the date and QuadKeys is correct.

Usage

format_fb_data(data, keep_format = NULL)

Arguments

data

A data.frame with a quadkey and date_time columns and other variables

keep_format

Vector of column names, besides date_time, day and quadkey, that you don't want to convert to a number.

Value

A data.frame without ⁠\N⁠, quadkey without scientific notation and a new column day and hour

Examples


data(result_read_fb_mobility_data)
format_fb_data(data = result_read_fb_mobility_data)

Get lat/long coordinates from the QuadKey

Description

Reads the QuadKey as a string and extracts the lat/long coordinates of the upper-left corner of the QuadKey.

Usage

get_qk_coord(data)

Arguments

data

A dataframe with a quadkey column.

Value

A sf POINT data.frame containing the tiles XY coordinates (tileX, tileY), the QuadKeys (quadkey), and a geometry column.

Examples


grid <- create_qk_grid(
  xmin = -59,
  xmax = -40,
  ymin = -38,
  ymax = -20,
  zoom = 6
)

# quadkey column in grid$data converted to geographic coordinates
grid_coords <- get_qk_coord(data = grid$data)

plot(grid_coords)

Get regular QuadKey polygon grid derived from the bounding box of the `quadkey` column of a data.frame.

Description

This function estimates the bounding box of the QuadKeys given in the quadkey column and adds the rows needed to complete a regular grid.

For a detailed explanation on how to use this and other similar quadkeyr functions, read the the vignette: https://docs.ropensci.org/quadkeyr/articles/facebook_mobility_csvs_to_raster_files.html

Usage

get_regular_polygon_grid(data)

Arguments

data

A data.frame with a quadkey column.

Value

A list with three elements:

data An sf POLYGON data.frame with all the QuadKeys within the bounding box of the quadkey column of a data.frame. Only the columns quadkey, tileX, tileY and geometry are returned.
num_rows The number of columns of the regular grid.
num_cols The number of rows of the regular grid.

Examples


# Data File
path <- paste0(
  system.file("extdata", package = "quadkeyr"),
  "/cityA_2020_04_15_0000.csv"
)
data <- read.csv(path)
data <- format_fb_data(data)

get_regular_polygon_grid(data = data)

Convert a grid of QuadKeys to square polygons

Description

The main argument of this function, the grid of geographic coordinates (lat/long WG84) represents the upper-left corner of the QuadKey. To transform these coordinates into square polygons, the function supplements the grid by adding a row and column of tiles. These points introduce QuadKeys located at the border of the area using the internal function complete_grid_for_polygons(). The function builds the polygons using all the points of the grid. Note that it's possible to associate each QuadKey with its square polygon.

Usage

grid_to_polygon(data)

Arguments

data

A sf POINT data.frame with a quadkey and geometry column.

Value

A sf POLYGON data.frame with a quadkey column.

Examples

grid <- create_qk_grid(
  xmin = -59,
  xmax = -57,
  ymin = -35,
  ymax = -34,
  zoom = 11
)

grid_coords <- get_qk_coord(data = grid$data)

polygrid <- grid_to_polygon(grid_coords)
polygrid

Ground resolution at a specified latitude and zoom level

Description

Determines the ground resolution (in meters per pixel) at a specified latitude and zoom level. For further information, refer to the Microsoft Bing Maps Tile System documentation.

Usage

ground_res(latitude, zoom)

Arguments

latitude

Latitude (in degrees) at which to measure the ground resolution.

zoom

Zoom or level of detail, from 1 (lowest detail) to 23 (highest detail).

Value

the ground resolution (meters / pixel)

References

https://learn.microsoft.com/en-us/bingmaps/articles/bing-maps-tile-system

Examples


ground_res(
  latitude = 0,
  zoom = 6
)

Convert lat/long coordinates to pixel XY coordinates

Description

Converts a point from latitude/longitude WGS-84 coordinates (in degrees) into pixel XY coordinates at a specified zoom level. For further information, refer to the Microsoft Bing Maps Tile System documentation.

Usage

latlong_to_pixelXY(lat, lon, zoom)

Arguments

lat

Latitude of the point, in degrees.

lon

Longitude of the point, in degrees.

zoom

Zoom or level of detail, from 1 (lowest detail) to 23 (highest detail).

Details

Converting latitude/longitude coordinates into a QuadKey and then back to latitude/longitude won't yield identical values, unless the initial latitude/longitude coordinates correspond to the upper-left Quadkey's pixel and tile XY coordinates at the same zoom level.

Understanding this distinction is crucial for the accurate use of these functions in coordinate conversions.

For a detailed explanation on how to use this and other similar quadkeyr functions, read the the vignette: https://docs.ropensci.org/quadkeyr/articles/quadkey_to_sf_conversion.html

Value

A list returning pixel X and pixel Y coordinates.

References

https://learn.microsoft.com/en-us/bingmaps/articles/bing-maps-tile-system

Examples


latlong_to_pixelXY(
  lat = -35,
  lon = -50,
  zoom = 6
)

Convert latitude/longitude coordinates into QuadKeys

Description

Converts a point from latitude/longitude WGS-84 coordinates (in degrees) into a Quadkey at a specified zoom level. For further information, refer to the Microsoft Bing Maps Tile System documentation.

Usage

latlong_to_quadkey(lat, lon, zoom)

Arguments

lat

Latitude of the point, in degrees.

lon

Longitude of the point, in degrees.

zoom

Zoom or level of detail, from 1 (lowest detail) to 23 (highest detail).

Details

Understanding this distinction is crucial for the accurate use of these functions in coordinate conversions.

For a detailed explanation on how to use this and other similar quadkeyr functions, read the the vignette: https://docs.ropensci.org/quadkeyr/articles/quadkey_to_sf_conversion.html

Value

A dataframe with latitude (lat), longitude (lon), zoom level (zoom) and the QuadKey as a string (quadkey).

References

https://learn.microsoft.com/en-us/bingmaps/articles/bing-maps-tile-system

Examples


latlong_to_quadkey(
  lat = 35.63051,
  lon = 139.69116,
  zoom = 20
)
latlong_to_quadkey(
  lat = c(-4, -25.33, -25.66),
  lon = c(-53, -60.33, -70.66),
  zoom = 4
)

Map scale (1 : N)

Description

Determines the map scale at a specified latitude, zoom level, and screen resolution. For further information, refer to the Microsoft Bing Maps Tile System documentation.

Usage

mapscale(latitude, zoom, screen_dpi)

Arguments

latitude

Latitude (in degrees) at which to measure the map scale.

zoom

Zoom or level of detail, from 1 (lowest detail) to 23 (highest detail).

screen_dpi

Resolution of the screen, in dots per inch.

Value

The map scale, expressed as the denominator N of the ratio 1 : N.

References

https://learn.microsoft.com/en-us/bingmaps/articles/bing-maps-tile-system

Examples


mapscale(
  latitude = 0,
  zoom = 6,
  screen_dpi = 96
)

Map size in pixels

Description

Determines the map width and height (in pixels) at a specified zoom level. For further information, refer to the Microsoft Bing Maps Tile System documentation.

Usage

mapsize(zoom)

Arguments

zoom

Zoom or level of detail, from 1 (lowest detail) to 23 (highest detail).

Value

The map width and height in pixels.

References

https://learn.microsoft.com/en-us/bingmaps/articles/bing-maps-tile-system

Examples


mapsize(zoom = 6)

Detect dates and hours missing in filenames

Description

Facebook mobility data is reported daily at 3 different hours (0, 8, 16). This function reads the data extracted from the current files and detects if any file for a particular day or hour is missing.

Usage

missing_combinations(data, hour_col = "hour", date_col = "day")

Arguments

data

A data.frame with one column for the raster's date and another for the hour. If not explicitly specified in the function's arguments, the column names are day and hour.

hour_col

The name of the column with the hour information.

date_col

The name of the column with the date information.

Value

A data.frame with the missing days and hours, if any.

Examples


# Sample dataset
data <- data.frame(
  country = c("US", "MX", "MX"), 
  day = c("2023-01-01", "2023-01-03", "2023-01-05"),
  hour = c(0, 8, 16)
)

missing_combinations(data)

Convert pixel XY coordinatess into lat/long coordinates.

Description

Converts a pixel from pixel XY coordinates at a specified zoom level into latitude/longitude WGS-84 coordinates (in degrees). For further information, refer to the Microsoft Bing Maps Tile System documentation.

Usage

pixelXY_to_latlong(pixelX, pixelY, zoom)

Arguments

pixelX

X coordinate of the point, in pixels.

pixelY

Y coordinates of the point, in pixels.

zoom

Zoom or level of detail, from 1 (lowest detail) to 23 (highest detail).

Details

Converting latitude/longitude coordinates into a QuadKey and then back to latitude/longitude won't yield identical values, unless the initial latitude/longitude coordinates correspond to the upper-left QuadKey's pixel and tile XY coordinates at the same zoom level.

Understanding this distinction is crucial for the accurate use of these functions in coordinate conversions.

For a detailed explanation on how to use this and other similar quadkeyr functions, read the the vignette: https://docs.ropensci.org/quadkeyr/articles/quadkey_to_sf_conversion.html

Value

A list with the longitude and latitude.

References

https://learn.microsoft.com/en-us/bingmaps/articles/bing-maps-tile-system

Examples


pixelXY_to_latlong(
  pixelX = 768,
  pixelY = 1280,
  zoom = 3
)

Convert pixel XY coordinates into tile XY coordinates

Description

Converts pixel XY coordinates into tile XY coordinates of the tile containing the specified pixel. For further information, refer to the Microsoft Bing Maps Tile System documentation.

Usage

pixelXY_to_tileXY(pixelX, pixelY)

Arguments

pixelX

Pixel X coordinate.

pixelY

Pixel Y coordinate.

Details

Understanding this distinction is crucial for the accurate use of these functions in coordinate conversions.

For a detailed explanation on how to use this and other similar quadkeyr functions, read the the vignette: https://docs.ropensci.org/quadkeyr/articles/quadkey_to_sf_conversion.html

Value

A list returning the tile X and tile Y coordinates.

References

https://learn.microsoft.com/en-us/bingmaps/articles/bing-maps-tile-system

Examples


pixelXY_to_tileXY(
  pixelX = 5916,
  pixelY = 9894
)

Create and save raster images for different dates and times

Description

Creates one raster by each date and time reported and saves it as a .tif.

Usage

polygon_to_raster(
  data,
  nx,
  ny,
  template,
  var = "percent_change",
  filename,
  path
)

Arguments

data

A sf POLYGON data.frame with the variable we want to represent in the raster.

nx

Integer; number of cells in x direction.

ny

Integer; number of cells in y direction.

template

A sf POLYGON data.frame

var

The column name of the variable to plot.

filename

Select a name for the file. The date and time will be included automatically in the name.

path

Path where the files should be stored.

Value

as many .tif files as dates and times in the dataset

Examples


files <- read_fb_mobility_files(
  path_to_csvs = paste0(system.file("extdata",
    package = "quadkeyr"
  ), "/"),
  colnames = c(
    "lat", "lon",
    "quadkey", "date_time",
    "n_crisis", "percent_change"
  ),
  coltypes = list(
    lat = "d",
    lon = "d",
    quadkey = "c",
    date_time = "T",
    n_crisis = "c",
    percent_change = "c"
  )
)

# Get a regular grid and create the polygons
regular_grid <- get_regular_polygon_grid(data = files)

# Keep only the QuadKeys reported
files_polygons <- files |>
  dplyr::inner_join(regular_grid$data,
    by = c("quadkey")
  )

# Generate the raster files
polygon_to_raster(
  data = files_polygons,
  nx = regular_grid$num_cols,
  ny = regular_grid$num_rows,
  template = files_polygons,
  var = "percent_change",
  filename = "cityA",
  path = paste0(
    system.file("extdata",
      package = "quadkeyr"
    ),
    "/"
  )
)

Launch the Shiny App

Description

This function launches the Shiny app.

Usage

qkmap_app()

Value

This function does not return any value. It launches the Shiny app.

Examples

if(interactive()){
qkmap_app()
}

Convert data.frame with `quadkey` column to a `sf` POLYGON data.frame

Description

Convert data.frame with quadkey column to a sf POLYGON data.frame

Usage

quadkey_df_to_polygon(data)

Arguments

data

A data.frame with a quadkey column

Value

The same original data.frame with a sf POLYGON data.frame with a geometry column.

Examples


# Quadkey as string
quadkey_to_polygon(quadkey = "213")

# QuadKeys as column in a data.frame
# get data file
path <- paste0(
  system.file("extdata", package = "quadkeyr"),
  "/cityA_2020_04_15_0000.csv"
)
data <- read.csv(path)
data <- format_fb_data(data)

quadkey_df_to_polygon(data = data)

Convert a string of Quadkey numbers to lat/long coordinates

Description

This function converts Quadkeys to latitude/longitude WGS-84 coordinates (in degrees). For further information, refer to the Microsoft Bing Maps Tile System documentation.

Usage

quadkey_to_latlong(quadkey_data)

Arguments

quadkey_data

A single QuadKey as a string or a vector with unique QuadKeys.

Details

Understanding this distinction is crucial for the accurate use of these functions in coordinate conversions.

For a detailed explanation on how to use this and other similar quadkeyr functions, read the the vignette: https://docs.ropensci.org/quadkeyr/articles/quadkey_to_sf_conversion.html

Value

A sf POINT data.frame with a quadkey column. The latitude/longitude coordinates represent the upper-left corner of the QuadKey.

References

https://learn.microsoft.com/en-us/bingmaps/articles/bing-maps-tile-system

Examples


quadkey_to_latlong(quadkey_data = "213")
quadkey_to_latlong(quadkey_data = c("213", "212", "210"))

Convert a QuadKey into a square polygon

Description

This functions creates a sf POLYGON data.frame from a QuadKey string.

Usage

quadkey_to_polygon(quadkey)

Arguments

quadkey

The QuadKey as a string

Value

A sf POLYGON data.frame with a quadkey and geometry column.

Examples


# Quadkey as string
quadkey_to_polygon(quadkey = "213")

# QuadKeys as column in a data.frame
# get data file
path <- paste0(
  system.file("extdata", package = "quadkeyr"),
  "/cityA_2020_04_15_0000.csv"
)
data <- read.csv(path)
data <- format_fb_data(data)

quadkey_df_to_polygon(data = data)

Convert a QuadKey into tile XY coordinates.

Description

For further information, refer to the Microsoft Bing Maps Tile System documentation.

Usage

quadkey_to_tileXY(quadkey)

Arguments

quadkey

A QuadKey as a single string.

Details

Converting latitude/longitude coordinates into a QuadKey and then back to latitude/longitude won't yield identical values, unless the initial latitude/longitude coordinates correspond to the upper-left QuadKey's pixel and tile XY coordinates at the same zoom level.

Understanding this distinction is crucial for the accurate use of these functions in coordinate conversions.

For a detailed explanation on how to use this and other similar quadkeyr functions, read the the vignette: https://docs.ropensci.org/quadkeyr/articles/quadkey_to_sf_conversion.html

Value

A list returning the tile X, tile Y coordinates and the zoom level.

References

https://learn.microsoft.com/en-us/bingmaps/articles/bing-maps-tile-system

Examples


quadkey_to_tileXY(quadkey = "213")

Read all the .csv files in a folder and format the data.

Description

This function reads all the .csv files in a particular folder. These files consistently contain identical columns, with variations only in location, day, and time. As a result, we can uniformly apply specific formatting to columns across these files.

Usage

read_fb_mobility_files(path_to_csvs, colnames, coltypes, keep_format = NULL)

Arguments

path_to_csvs

Path to the folder where the .csv files are stored

colnames

Columns to include in the results (as character). For more information go to readr::read_csv()

coltypes

Column specifications (as strings). See vignette("readr", package = "readr") for more details. documentation.

keep_format

Vector of column names, besides date_time, day and quadkey, that you don't want to convert to a number.

Value

A data.frame with the information of all the files read.

Examples


files <- read_fb_mobility_files(
  path_to_csvs = paste0(system.file("extdata",
    package = "quadkeyr"
  ), "/"),
  colnames = c( # The columns not listed here will be omitted
    "lat",
    "lon",
    "quadkey",
    "date_time",
    "n_crisis",
    "percent_change",
    "day",
    "hour"
  ),
  coltypes = list(
    lat = "d",
    lon = "d",
    quadkey = "c",
    date_time = "T",
    n_crisis = "c",
    percent_change = "c",
    day = "D",
    hour = "i"
  )
)

head(files)

Convert a incomplete QuadKey `sf` POINT data.frame into a regular grid.

Description

This function completes sf POINT data.frame grid of QuadKeys using the bounding box of the data provided.

Usage

regular_qk_grid(data)

Arguments

data

A sf POINT data.frame

Value

A list with three elements:

data A sf POINT data.frame, with the rows needed to complete the grid.
num_rows The number of columns of the regular grid.
num_cols The number of rows of the regular grid.

Examples


quadkey_vector <- c("213", "210", "211")

qtll <- quadkey_to_latlong(quadkey = quadkey_vector)

regular_qk_grid(qtll)

Dataset with (fake) Facebook mobility data

Description

A data.frame similar to a the potential output of read_fb_mobility_files.

Usage

result_read_fb_mobility_data

Format

`result_read_fb_mobility_data`

A data frame with 134,492 rows and 9 columns:

lat: Latitude of the QuadKey centroid
lon: Longitude of the QuadKey centroid
quadkey: QuadKey as a string
country: Country name
date_time: Date in format %Y-%m-%d %H%M
n_crisis: Variable
percent_change: Variable
day: Day in format %Y-%m-%d
hour: Hour of the day as a number between 1 and 24

Convert tile XY coordinates into pixel XY coordinates

Description

Converts tile XY coordinates into pixel XY coordinates of the upper-left pixel of the specified tile. For further information, refer to the Microsoft Bing Maps Tile System documentation.

Usage

tileXY_to_pixelXY(tileX, tileY)

Arguments

tileX

Tile X coordinate.

tileY

Tile Y coordinate.

Details

Understanding this distinction is crucial for the accurate use of these functions in coordinate conversions.

For a detailed explanation on how to use this and other similar quadkeyr functions, read the the vignette: https://docs.ropensci.org/quadkeyr/articles/quadkey_to_sf_conversion.html

Value

A list returning the pixel X and pixel Y coordinates.

References

https://learn.microsoft.com/en-us/bingmaps/articles/bing-maps-tile-system

Examples


tileXY_to_pixelXY(
  tileX = 3,
  tileY = 5
)

Convert tile XY coordinates into a QuadKey.

Description

Converts tile XY coordinates into a QuadKey at a specified zoom level. For further information, refer to the Microsoft Bing Maps Tile System documentation.

Usage

tileXY_to_quadkey(tileX, tileY, zoom)

Arguments

tileX

Tile X coordinate.

tileY

Tile Y coordinate.

zoom

Zoom or level of detail, from 1 (lowest detail) to 23 (highest detail).

Details

Understanding this distinction is crucial for the accurate use of these functions in coordinate conversions.

For a detailed explanation on how to use this and other similar quadkeyr functions, read the the vignette: https://docs.ropensci.org/quadkeyr/articles/quadkey_to_sf_conversion.html

Value

The QuadKey as a string.

References

https://learn.microsoft.com/en-us/bingmaps/articles/bing-maps-tile-system

Examples


tileXY_to_quadkey(
  tileX = 23,
  tileY = 38,
  zoom = 6
)

quadkeyr: Generate Raster Images from QuadKey-Identified Datasets

Description

Author(s)

See Also

Add the rows needed to complete a regular QuadKey polygon grid derived from the bounding box of the quadkey column of a data.frame.

Description

Usage

Arguments

Value

Examples

Apply a 7 day lag to the variable n_crisis

Description

Usage

Arguments

Value

Examples

Create grid of QuadKeys for a particular zoom or level of detail.

Description

Usage

Arguments

Value

Examples

Create a stars raster

Description

Usage

Arguments

Value

See Also

Examples

QuadKey-identified Dataset

Description

Usage

Format

data_provided

Format the Facebook mobility data

Description

Usage

Arguments

Value

See Also

Examples

Get lat/long coordinates from the QuadKey

Description

Usage

Arguments

Value

See Also

Examples

Get regular QuadKey polygon grid derived from the bounding box of the quadkey column of a data.frame.

Description

Usage

Arguments

Value

Examples

Convert a grid of QuadKeys to square polygons

Description

Usage

Arguments

Value

Examples

Ground resolution at a specified latitude and zoom level

Description

Usage

Arguments

Value

References

Examples

Convert lat/long coordinates to pixel XY coordinates

Description

Usage

Arguments

Details

Value

References

Examples

Convert latitude/longitude coordinates into QuadKeys

Description

Usage

Arguments

Details

Add the rows needed to complete a regular QuadKey polygon grid derived from the bounding box of the `quadkey` column of a data.frame.

Apply a 7 day lag to the variable `n_crisis`

Create a `stars` raster

`data_provided`

Get regular QuadKey polygon grid derived from the bounding box of the `quadkey` column of a data.frame.

Convert data.frame with `quadkey` column to a `sf` POLYGON data.frame