我刚开始学习R而我正在尝试创建一张地图,显示康涅狄格州每个城镇的学生人数。我有一个.csv的位置和注册信息,如下所示:
name lon lat resStudent
1 ANDOVER -72.37472 41.73278 657
2 ANSONIA -73.07900 41.34621 2999
3 ASHFORD -72.12162 41.87307 736
4 AVON -72.83052 41.80962 3563
5 BARKHAMSTED -72.97222 41.92917 680
6 BEACON FALLS -73.06176 41.44265 1039
7 BERLIN -72.78064 41.61460 3165
8 BETHANY -72.99250 41.42556 1028
9 BETHEL -73.41396 41.37123 3034
10 BETHLEHEM -73.20861 41.63917 490
11 BLOOMFIELD -72.73336 41.83945 2484
我已经能够使用以下代码生成我想要覆盖此信息的地图:
tempMap <- get_openstreetmap(bbox = c(left = -73.8, bottom = 40.9, right = -71.7, top = 42.1), scale = 829486, color = "bw")
ggmap(tempMap)
我遇到了将两者结合起来的问题。这是我正在使用的代码:
enrollData<-read.csv("enrollData.csv")
enrollMap <- tempMap + geom_point(data = enrollData,aes(x = lon, y = lat, size = resStudent)
运行后,我收到一条错误消息:
Error in Ops.raster(tempMap, geom_point(data = enrollData, aes(x = lon, :
Operator not meaningful for raster objects
有关如何解决此问题的任何想法?
答案 0 :(得分:4)
您需要先致电ggmap
创建基础层。以下应该有效:
ggmap(tempMap) + geom_point(data = enrollData,aes(x = lon, y = lat, size = resStudent)