纬度经度坐标到R中的州代码
有没有一种快速的方法来将经度和纬度坐标转换为R中的州代码?我一直使用zipcode包作为查找表,但当我查询很多纬度/长度值时,它太慢纬度经度坐标到R中的州代码
如果不是在R有任何方式使用谷歌地理编码器或任何其他类型快速查询服务?
谢谢!
这是一个函数,它在低48个状态内采用lat-long的data.frame,并为每个点返回它所在的状态。
大部分功能的简单准备由sp
包over()
函数,该函数计算的点和面的“交集”的真正繁重所需的SpatialPoints
和SpatialPolygons
对象:
library(sp)
library(maps)
library(maptools)
# The single argument to this function, pointsDF, is a data.frame in which:
# - column 1 contains the longitude in degrees (negative in the US)
# - column 2 contains the latitude in degrees
latlong2state <- function(pointsDF) {
# Prepare SpatialPolygons object with one SpatialPolygon
# per state (plus DC, minus HI & AK)
states <- map('state', fill=TRUE, col="transparent", plot=FALSE)
IDs <- sapply(strsplit(states$names, ":"), function(x) x[1])
states_sp <- map2SpatialPolygons(states, IDs=IDs,
proj4string=CRS("+proj=longlat +datum=WGS84"))
# Convert pointsDF to a SpatialPoints object
pointsSP <- SpatialPoints(pointsDF,
proj4string=CRS("+proj=longlat +datum=WGS84"))
# Use 'over' to get _indices_ of the Polygons object containing each point
indices <- over(pointsSP, states_sp)
# Return the state names of the Polygons object containing each point
stateNames <- sapply([email protected], function(x) [email protected])
stateNames[indices]
}
# Test the function using points in Wisconsin and Oregon.
testPoints <- data.frame(x = c(-90, -120), y = c(44, 44))
latlong2state(testPoints)
[1] "wisconsin" "oregon" # IT WORKS
我必须将wgs84更改为WGS84才能使此示例正常工作。 – lever 2016-03-08 23:11:19
@lever感谢您指出。不知道什么时候(以及哪里)发生了变化。无论如何,我现在编辑来解决它。 – 2016-03-08 23:17:27
请参阅sp包中的内容。您需要将状态边界作为SpatialPolygonDataFrame。
你能做到这一点的R.
几行library(sp)
library(rgdal)
#lat and long
Lat <- 57.25
Lon <- -9.41
#make a data frame
coords <- as.data.frame(cbind(Lon,Lat))
#and into Spatial
points <- SpatialPoints(coords)
#SpatialPolygonDataFrame - I'm using a shapefile of UK counties
counties <- readOGR(".", "uk_counties")
#assume same proj as shapefile!
proj4string(points) <- proj4string(counties)
#get county polygon point is in
result <- as.character(over(points, counties)$County_Name)
谢谢!这更简单:) – 2016-08-04 13:18:02
这里也看到我的答案,使用'ggmap :: revgeocode':https://*.com/questions/46150851/how-to-get-california-县位置从-LAT itude-and-long-information/46151310#46151310 – 2017-09-11 08:51:12