r - 错误 : Discrete value supplied to continuous scale

Question

我正在使用 ggmap 处理马达加斯加 map

myMap <- get_map(location=k, source="stamen", maptype="toner", crop=FALSE, 
                 zoom=16)

并根据 x y 纬度/经度网格在该 map 上绘制点

ggmap(myMap) + geom_point(data=GPS, aes(x = 'Lon', y ='Lat'))
ggplot(data=GPS, aes(x=Lon,y=Lat)) + geom_point()

从看起来像这样的数据

 Tree.ID       Type       Species       Lat      Lon Foraged Plot
       7   deadwood      Dracaena -21.37413 47.86700       N    1
       8   deadwood       Bivinia -21.37408 47.86696       N    1
       9   deadwood Beilschmiedia -21.37396 47.86691       N    1
      10 live trunk        Ocotea -21.37410 47.86690       N    1
      12   deadwood   Tambourissa -21.37418 47.86696       N    1
      13 live trunk      Canarium -21.37422 47.86691       N    1

但是我得到这个错误:

Error: Discrete value supplied to continuous scale

我该怎么办？

Answer 1

您将字符串 "Lon" 和 "Lat" 传递给 x 和 y 而不是而不是传递 Lon 和 Lat 本身。去掉引号，你应该没问题。

d <- read.table(header=T, text='
 Tree.ID      Type       Species       Lat      Lon Foraged Plot
       7  deadwood      Dracaena -21.37413 47.86700       N    1
       8  deadwood       Bivinia -21.37408 47.86696       N    1
       9  deadwood Beilschmiedia -21.37396 47.86691       N    1
      10 livetrunk        Ocotea -21.37410 47.86690       N    1
      12  deadwood   Tambourissa -21.37418 47.86696       N    1
      13 livetrunk      Canarium -21.37422 47.86691       N    1')

library(ggmap)

myMap <- get_map(location=colMeans(d[, c('Lon', 'Lat')]), source="stamen", 
                 maptype="toner", crop=FALSE, zoom=16)
ggmap(myMap) + geom_point(aes(x = Lon, y = Lat), data=d)