r - 将字符 lat/lng 值转换为数字

Question

我有一个数据框 df，其中包含带有东、西、北和南指定的纬度和经度字符值。通过转换 Latitude 和 Longitude 将 df 转换为所需输出 df2 的优雅方法是什么？列作为数字并使任何 South 和 West 值为负？

#MRE
library(tibble)

#input data set
df <- tribble(
  ~Country, ~Capital, ~Latitude, ~Longitude,
  "Afghanistan", "Kabul", "34.28N", "69.11E",
  "Albania", "Tirane", "41.18N", "19.49E",
  "Algeria", "Algiers", "36.42N", "03.08E",
  "American Samoa", "Pago Pago", "14.16S", "170.43W",
  "Andorra", "Andorra la Vella", "42.31N", "01.32E",
  "Angola", "Luanda", "08.50S", "13.15E" 
  )

# desired output

df2 <- tribble(
  ~Country, ~Capital, ~Latitude, ~Longitude,
  "Afghanistan", "Kabul", 34.28, 69.11,
  "Albania", "Tirane", 41.18, 19.49,
  "Algeria", "Algiers", 36.42, 03.08,
  "American Samoa", "Pago Pago", -14.16, -170.43,
  "Andorra", "Andorra la Vella", 42.31, 01.32,
  "Angola", "Luanda", -08.50, -13.15 
  )

提前感谢您的友好建议

Answer 1

library(dplyr)
df %>%
  mutate_at(vars(Latitude, Longitude),
            funs(as.numeric(gsub("[NE]$", "", gsub("^(.*)[WS]$", "-\\1", .)))))
# # A tibble: 6 × 4
#          Country          Capital Latitude Longitude
#            <chr>            <chr>    <dbl>     <dbl>
# 1    Afghanistan            Kabul    34.28     69.11
# 2        Albania           Tirane    41.18     19.49
# 3        Algeria          Algiers    36.42      3.08
# 4 American Samoa        Pago Pago   -14.16   -170.43
# 5        Andorra Andorra la Vella    42.31      1.32
# 6         Angola           Luanda    -8.50     13.15