从坐标大数据集(一百万个或更多坐标)获取时区的最快方法

我碰巧找到了 lutz tz_lookup_coords() . 使用此函数可以通过两种方式设置方法。一个是 method = "fast" 另一个是 method = "accurate"

library(lutz) 
set.seed(111)
data <- data.table(latitude=sample(seq(47,52,by=0.001), 1000000, replace = TRUE),
                   longitude=sample(seq(8,23,by=0.001), 1000000, replace = TRUE))

system.time(data[, timezone := tz_lookup_coords(lat = latitude, lon = longitude, method = "fast")])

#user  system elapsed 
#6.46    3.42    9.92 

#Warning message:
#Using 'fast' method. This can cause inaccuracies in timezones
#near boundaries away from populated ares. Use the 'accurate'
#method if accuracy is more important than speed. 

system.time(data[, timezone := tz_lookup_coords(lat = latitude, lon = longitude, method = "accurate")])

#  user  system elapsed 
#154.44    0.18  154.93