Nothing
R/getInfra.R
In infra: An Infrastructure Proxy Function
#' An Infrastructure Proxy Function
#'
#' This function takes latitude and longitude coordinates from a data frame
#' and downloads images from map servers for those coordinates.
#' It will return the file sizes of those map images which can
#' be used as a useful proxy for the level of infrastructure
#' development. Map servers currently used are Google, Bing
#' and Openstreetmap.
#' @param dataFrame The name of your data frame
#' @param server The map server you want to use. Options are google, bing, and open. Defaults to google
#' @param zoom The zoom level you want to use. Defaults to 14. Valid values for google are 0 to 22; values for bing are 1 to 19; values for open are 0 to 19
#' @keywords infrastructure maps google bing openstreetmap
#' @export
#' @examples
#' # In this example, we'll build a very low resolution (two degrees per grid cell) grid of Japan,
#' # retrieve the map values from Bing at zoom level 14, and render a simple map.
#'
#' # First, define the latitude and longitude bounds of Japan and create a data frame.
#' # (This uses a very restricted version of the territory of Japan for the sake of speed.)
#'
#' lats <- rep(rev(seq(32,44, by=2)), each=7)
#' lngs <- rep(seq(130,142, by=2), 7)
#'
#' coords <- data.frame(lats,lngs)
#'
#' infraBing <- getInfra(dataFrame = coords, zoom=14, server="bing")
#'
#' # Now that we have the values in the newly-created infraBing
#' # variable we can plot them. First, we need to define our colour
#' # gamut, running from 0 to the maximum map value retrieved.
#'
#' grey <- gray(0:max(infraBing) / max(infraBing))
#'
#' # Now we can plot.
#'
#' png(filename="japanInfraBing.png", width=480, height=480, units="px")
#' plot(lngs, lats, col=grey[infraBing], pch=15, cex=14)
#' dev.off()
getInfra <- function(dataFrame=NULL, server="google", zoom=14) {
dataFrameMissing = 0
if (missing(dataFrame)) {
print ("No data frame declared.", quote=FALSE)
print ("Syntax is: getInfra(dataFrame, server, zoom)", quote=FALSE)
print ("Exiting.", quote=FALSE)
dataFrameMissing = 1
}
if (dataFrameMissing == 0) {
if (missing(server)) {
print ("Server was not declared. Options are 'google', 'bing' or 'open'. Defaulting to google.", quote=FALSE)
}
if (missing(zoom)) {
print ("Zoom was not declared. Defaulting to 14. For google, valid values are 0 (whole world) to 22 (street level); 1 to 19 for bing; 0 to 19 for open.", quote=FALSE)
}
}
serverFound = 0
if (server == "google") {
serverFound = 1
lineCounter = 1
googleFileSize <- NULL
progressBar <- txtProgressBar(min = 0, max = length(dataFrame$lat), style = 3)
while(lineCounter < (length(dataFrame$lat) + 1)) {
degLat = dataFrame$lat[lineCounter]
degLng = dataFrame$lng[lineCounter]
zValue = zoom
mapSize = 2^zValue
radLat = degLat * (pi / 180)
pixelY = 0.5*(log((1+sin(radLat))/(1-sin(radLat))))
pixelY = pixelY / (pi / (mapSize / 2))
pixelY = (mapSize / 2) - pixelY
pixelY = round(pixelY)
pixelX = (mapSize / 2) + (degLng * ((mapSize / 2) / 180))
pixelX = round(pixelX)
urlToGet = paste("http://mt0.google.com/vt/lyrs=m@0&hl=en&x=", pixelX, "&y=", pixelY, "&z=", zValue, sep="")
download.file(url=urlToGet, destfile="googleFileContents.txt", quiet = TRUE, mode = "w", cacheOK = TRUE, extra = getOption("download.file.extra"))
fileSize = file.info("googleFileContents.txt")["size"]$size
googleFileSize = c(googleFileSize , fileSize)
lineCounter = lineCounter + 1
setTxtProgressBar(progressBar, lineCounter)
}
return(googleFileSize)
file.remove("googleFileContents.txt")
close(progressBar)
}
if (server == "bing") {
serverFound = 1
lineCounter = 1
bingFileSize <- NULL
progressBar <- txtProgressBar(min = 0, max = length(dataFrame$lat), style = 3)
while(lineCounter < (length(dataFrame$lat) + 1)) {
inputLat = dataFrame$lat[lineCounter]
inputLng = dataFrame$lng[lineCounter]
minLat = -85.05112878
maxLat = 85.05112878
imageWidthAndHeight = bitwShiftL(256, zoom)
# first, convert lat lng to pixel x y
# make sure they fit in the MS bounds
if (inputLat < minLat) {
inputLat = minLat
}
if (inputLat > maxLat) {
inputLat = maxLat
}
firstX = (inputLng + 180) / 360
sinLat = sin(inputLat * pi / 180)
firstY = 0.5 - log((1 + sinLat) / (1 - sinLat)) / (4 * pi)
pixelX = round(firstX * imageWidthAndHeight)
pixelY = round(firstY * imageWidthAndHeight)
tileX = pixelX / 256
tileY = pixelY / 256
quadKey = NULL
for(i in zoom:1){
digit = 0
mask = bitwShiftL(1,i-1)
if (bitwAnd(tileX, mask) != 0) {
digit = digit + 1
}
if (bitwAnd(tileY, mask) != 0) {
digit = digit + 2
}
quadKey = paste(quadKey, digit, sep="")
}
urlToGet = paste("http://ak.dynamic.t0.tiles.virtualearth.net/comp/ch/", quadKey, "?mkt=en-gb&it=G,VE,BX,L,LA", sep="")
download.file(url=urlToGet, destfile="bingFileContents.txt", quiet = TRUE, mode = "w", cacheOK = TRUE, extra = getOption("download.file.extra"))
fileSize = file.info("bingFileContents.txt")["size"]$size
bingFileSize = c(bingFileSize, fileSize)
lineCounter = lineCounter + 1
setTxtProgressBar(progressBar, lineCounter)
}
return(bingFileSize)
file.remove("bingFileContents.txt")
close(progressBar)
}
if (server == "open") {
serverFound = 1
lineCounter = 1
openMapFileSize <- NULL
progressBar <- txtProgressBar(min = 0, max = length(dataFrame$lat), style = 3)
while(lineCounter < (length(dataFrame$lat) + 1)) {
inputLat = dataFrame$lat[lineCounter]
inputLng = dataFrame$lng[lineCounter]
numberOfTiles = bitwShiftL(1, zoom)
inputLngMod = inputLng + 180
pixX = (numberOfTiles / 360) * inputLngMod
inputLatMod = inputLat * pi / 180
n <- 2 ^ zoom
pixY = floor((1 - log(tan(inputLatMod) + (1 / cos(inputLatMod))) / pi) / 2 * n)
pixX = round(pixX)
pixY = round(pixY)
urlToGet = paste("http://c.tile.openstreetmap.org/", zoom, "/", pixX, "/", pixY, ".png", sep="")
openFileNotFound = 0
tryCatch(download.file(url=urlToGet, destfile="openFileContents.txt", quiet = TRUE, mode = "w", cacheOK = TRUE, extra = getOption("download.file.extra")),
warning = function(w) {
Sys.sleep(10)
print("Unable to download image from openstreetmap. Retrying after 10 seconds...", quote=FALSE)
tryCatch(download.file(url=urlToGet, destfile="openFileContents.txt", quiet = TRUE, mode = "w", cacheOK = TRUE, extra = getOption("download.file.extra")),
warning = function(w2) {
openFileNotFound = 1
print("Unsuccessful. This location will be coded as NA.", quote=FALSE)
}
)
}
)
if (openFileNotFound == 0) {
fileSize = file.info("openFileContents.txt")["size"]$size
}
if (openFileNotFound == 1) {
fileSize = "NA";
}
openMapFileSize = c(openMapFileSize, fileSize)
lineCounter = lineCounter + 1
setTxtProgressBar(progressBar, lineCounter)
}
return(openMapFileSize)
file.remove("openFileContents.txt")
close(progressBar)
}
if (serverFound == 0) {
print (paste("Server name (", server, ") not recognised. Options are 'google', 'bing', 'open'. Exiting."), quote=FALSE)
}
}
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infra documentation built on May 2, 2019, 8:55 a.m.
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#' An Infrastructure Proxy Function
#'
#' This function takes latitude and longitude coordinates from a data frame
#' and downloads images from map servers for those coordinates.
#' It will return the file sizes of those map images which can
#' be used as a useful proxy for the level of infrastructure
#' development. Map servers currently used are Google, Bing
#' and Openstreetmap.
#' @param dataFrame The name of your data frame
#' @param server The map server you want to use. Options are google, bing, and open. Defaults to google
#' @param zoom The zoom level you want to use. Defaults to 14. Valid values for google are 0 to 22; values for bing are 1 to 19; values for open are 0 to 19
#' @keywords infrastructure maps google bing openstreetmap
#' @export
#' @examples
#' # In this example, we'll build a very low resolution (two degrees per grid cell) grid of Japan,
#' # retrieve the map values from Bing at zoom level 14, and render a simple map.
#'
#' # First, define the latitude and longitude bounds of Japan and create a data frame.
#' # (This uses a very restricted version of the territory of Japan for the sake of speed.)
#'
#' lats <- rep(rev(seq(32,44, by=2)), each=7)
#' lngs <- rep(seq(130,142, by=2), 7)
#'
#' coords <- data.frame(lats,lngs)
#'
#' infraBing <- getInfra(dataFrame = coords, zoom=14, server="bing")
#'
#' # Now that we have the values in the newly-created infraBing
#' # variable we can plot them. First, we need to define our colour
#' # gamut, running from 0 to the maximum map value retrieved.
#'
#' grey <- gray(0:max(infraBing) / max(infraBing))
#'
#' # Now we can plot.
#'
#' png(filename="japanInfraBing.png", width=480, height=480, units="px")
#' plot(lngs, lats, col=grey[infraBing], pch=15, cex=14)
#' dev.off()
getInfra <- function(dataFrame=NULL, server="google", zoom=14) {
dataFrameMissing = 0
if (missing(dataFrame)) {
print ("No data frame declared.", quote=FALSE)
print ("Syntax is: getInfra(dataFrame, server, zoom)", quote=FALSE)
print ("Exiting.", quote=FALSE)
dataFrameMissing = 1
}
if (dataFrameMissing == 0) {
if (missing(server)) {
print ("Server was not declared. Options are 'google', 'bing' or 'open'. Defaulting to google.", quote=FALSE)
}
if (missing(zoom)) {
print ("Zoom was not declared. Defaulting to 14. For google, valid values are 0 (whole world) to 22 (street level); 1 to 19 for bing; 0 to 19 for open.", quote=FALSE)
}
}
serverFound = 0
if (server == "google") {
serverFound = 1
lineCounter = 1
googleFileSize <- NULL
progressBar <- txtProgressBar(min = 0, max = length(dataFrame$lat), style = 3)
while(lineCounter < (length(dataFrame$lat) + 1)) {
degLat = dataFrame$lat[lineCounter]
degLng = dataFrame$lng[lineCounter]
zValue = zoom
mapSize = 2^zValue
radLat = degLat * (pi / 180)
pixelY = 0.5*(log((1+sin(radLat))/(1-sin(radLat))))
pixelY = pixelY / (pi / (mapSize / 2))
pixelY = (mapSize / 2) - pixelY
pixelY = round(pixelY)
pixelX = (mapSize / 2) + (degLng * ((mapSize / 2) / 180))
pixelX = round(pixelX)
urlToGet = paste("http://mt0.google.com/vt/lyrs=m@0&hl=en&x=", pixelX, "&y=", pixelY, "&z=", zValue, sep="")
download.file(url=urlToGet, destfile="googleFileContents.txt", quiet = TRUE, mode = "w", cacheOK = TRUE, extra = getOption("download.file.extra"))
fileSize = file.info("googleFileContents.txt")["size"]$size
googleFileSize = c(googleFileSize , fileSize)
lineCounter = lineCounter + 1
setTxtProgressBar(progressBar, lineCounter)
}
return(googleFileSize)
file.remove("googleFileContents.txt")
close(progressBar)
}
if (server == "bing") {
serverFound = 1
lineCounter = 1
bingFileSize <- NULL
progressBar <- txtProgressBar(min = 0, max = length(dataFrame$lat), style = 3)
while(lineCounter < (length(dataFrame$lat) + 1)) {
inputLat = dataFrame$lat[lineCounter]
inputLng = dataFrame$lng[lineCounter]
minLat = -85.05112878
maxLat = 85.05112878
imageWidthAndHeight = bitwShiftL(256, zoom)
# first, convert lat lng to pixel x y
# make sure they fit in the MS bounds
if (inputLat < minLat) {
inputLat = minLat
}
if (inputLat > maxLat) {
inputLat = maxLat
}
firstX = (inputLng + 180) / 360
sinLat = sin(inputLat * pi / 180)
firstY = 0.5 - log((1 + sinLat) / (1 - sinLat)) / (4 * pi)
pixelX = round(firstX * imageWidthAndHeight)
pixelY = round(firstY * imageWidthAndHeight)
tileX = pixelX / 256
tileY = pixelY / 256
quadKey = NULL
for(i in zoom:1){
digit = 0
mask = bitwShiftL(1,i-1)
if (bitwAnd(tileX, mask) != 0) {
digit = digit + 1
}
if (bitwAnd(tileY, mask) != 0) {
digit = digit + 2
}
quadKey = paste(quadKey, digit, sep="")
}
urlToGet = paste("http://ak.dynamic.t0.tiles.virtualearth.net/comp/ch/", quadKey, "?mkt=en-gb&it=G,VE,BX,L,LA", sep="")
download.file(url=urlToGet, destfile="bingFileContents.txt", quiet = TRUE, mode = "w", cacheOK = TRUE, extra = getOption("download.file.extra"))
fileSize = file.info("bingFileContents.txt")["size"]$size
bingFileSize = c(bingFileSize, fileSize)
lineCounter = lineCounter + 1
setTxtProgressBar(progressBar, lineCounter)
}
return(bingFileSize)
file.remove("bingFileContents.txt")
close(progressBar)
}
if (server == "open") {
serverFound = 1
lineCounter = 1
openMapFileSize <- NULL
progressBar <- txtProgressBar(min = 0, max = length(dataFrame$lat), style = 3)
while(lineCounter < (length(dataFrame$lat) + 1)) {
inputLat = dataFrame$lat[lineCounter]
inputLng = dataFrame$lng[lineCounter]
numberOfTiles = bitwShiftL(1, zoom)
inputLngMod = inputLng + 180
pixX = (numberOfTiles / 360) * inputLngMod
inputLatMod = inputLat * pi / 180
n <- 2 ^ zoom
pixY = floor((1 - log(tan(inputLatMod) + (1 / cos(inputLatMod))) / pi) / 2 * n)
pixX = round(pixX)
pixY = round(pixY)
urlToGet = paste("http://c.tile.openstreetmap.org/", zoom, "/", pixX, "/", pixY, ".png", sep="")
openFileNotFound = 0
tryCatch(download.file(url=urlToGet, destfile="openFileContents.txt", quiet = TRUE, mode = "w", cacheOK = TRUE, extra = getOption("download.file.extra")),
warning = function(w) {
Sys.sleep(10)
print("Unable to download image from openstreetmap. Retrying after 10 seconds...", quote=FALSE)
tryCatch(download.file(url=urlToGet, destfile="openFileContents.txt", quiet = TRUE, mode = "w", cacheOK = TRUE, extra = getOption("download.file.extra")),
warning = function(w2) {
openFileNotFound = 1
print("Unsuccessful. This location will be coded as NA.", quote=FALSE)
}
)
}
)
if (openFileNotFound == 0) {
fileSize = file.info("openFileContents.txt")["size"]$size
}
if (openFileNotFound == 1) {
fileSize = "NA";
}
openMapFileSize = c(openMapFileSize, fileSize)
lineCounter = lineCounter + 1
setTxtProgressBar(progressBar, lineCounter)
}
return(openMapFileSize)
file.remove("openFileContents.txt")
close(progressBar)
}
if (serverFound == 0) {
print (paste("Server name (", server, ") not recognised. Options are 'google', 'bing', 'open'. Exiting."), quote=FALSE)
}
}
Try the infra package in your browser
Any scripts or data that you put into this service are public.
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
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