如何将openstreetmap与R中的点结合起来

I'm just starting off learning R and I'm attempting to create a map that shows the number of students in each town in Connecticut. I've got a .csv of location and enrollment info that looks like this:

我刚开始学习R，我正在尝试绘制一张地图，显示康涅狄格州每个城镇的学生人数。我有一个。csv的位置和注册信息是这样的:

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

I've been able to generate the map that I'd like to overlay this information on using the following code:

我已经能够生成地图，我想用下面的代码覆盖这个信息:

tempMap <- get_openstreetmap(bbox = c(left = -73.8, bottom = 40.9, right = -71.7, top = 42.1), scale = 829486, color = "bw")
ggmap(tempMap)

I'm running in to a problem combining the two. Here is the code I'm using:

我遇到了一个把两者结合起来的问题。下面是我使用的代码:

enrollData<-read.csv("enrollData.csv")   
enrollMap <- tempMap + geom_point(data = enrollData,aes(x = lon, y = lat, size = resStudent)

After this runs, I get an error message that reads:

运行完之后，我得到一条错误消息:

Error in Ops.raster(tempMap, geom_point(data = enrollData, aes(x = lon,  : 
  Operator not meaningful for raster objects

Any ideas for how to fix this?

有办法解决这个问题吗?

1 个解决方案

#1

You need to call ggmap first create the base layer. The following should work:

您需要首先调用ggmap来创建基层。以下工作:

ggmap(tempMap) + geom_point(data = enrollData,aes(x = lon, y = lat, size = resStudent)