使用 Leaflet 时的可视化问题

Question

我有两个数据框如下：

PickUP <- data.frame(pickuplong = c(-73.93909 ,-73.94189 ,-73.93754,-73.91638,-73.92792 ,-73.88634), pickuplat =c(40.84408,40.83841,40.85311,40.84966,40.86284,40.85628)) 

Dropoff <- data.frame(pickuplong = c(-73.93351 ,-73.93909 ,-73.93909 ,-73.80747,-73.95722,-73.91880), pickuplat =c(40.76621,40.84408,40.85311,40.69951,40.68877,40.75917), Droplong =c(-73.91300,-73.96259 ,-73.94870,-73.93860,-73.93633, -73.90690), Droplat =c(40.77777,40.77488 ,40.78493,40.84463,40.75977,40.77013)) 

我尝试在 pickup 数据帧 中找到在 dropoff dataframe 中重复的接送坐标（经度和纬度）。我有下面的代码，但我得到了这个错误：

library(sp)
library(rgdal)
library(leaflet)
library(mapview)
library(dplyr)
a <- semi_join(Dropoff , PickUP , by = c("pickuplong","pickuplat"))
a$ID <- 1:nrow(a) 
Dropoff_p <- a[, c("ID", "Pickup_longitude", "Pickup_latitude")]
Dropoff_d <- a[, c("ID", "Dropoff_longitude", "Dropoff_latitude")]
coordinates(Dropoff_p) <- ~Pickup_longitude + Pickup_latitude
coordinates(Dropoff_d) <- ~Dropoff_longitude + Dropoff_latitude
proj4string(Dropoff_p) <- CRS("+init=epsg:4326")
proj4string(Dropoff_d) <- CRS("+init=epsg:4326")
map_p <- mapview(Dropoff_p, color = "red")
map_d <- mapview(Dropoff_d, color = "blue")
map_p + map_d

我的错误是：

$tmp, "ID", value = c(1L, 0L)) 中的错误： 替换有 2 行，数据有 0 总结期间错误：无法打开 连接

Answer 1

当对数据框进行子集化时，您必须使用相同的列名。我更改了Dropoff_p、Dropoff_d、coordinates(Dropoff_p)和proj4string(Dropoff_d)中的列名，然后你的脚本就可以工作了。

此外，mapview 软件包刚刚有了新的更新。如果需要，您可以将您的 mapview 更新为版本 2.0.1。您还可以添加col.regions = "red" 和col.regions = "blue"，因为似乎在新版本下color 参数只会改变一个点的轮廓。要更改填充颜色，请使用col.regions。

library(sp)
library(rgdal)
library(leaflet)
library(mapview)
library(dplyr)

a <- semi_join(Dropoff , PickUP , by = c("pickuplong","pickuplat"))
a$ID <- 1:nrow(a) 
Dropoff_p <- a[, c("ID", "pickuplong", "pickuplat")]
Dropoff_d <- a[, c("ID", "Droplong", "Droplat")]
coordinates(Dropoff_p) <- ~pickuplong + pickuplat
coordinates(Dropoff_d) <- ~Droplong + Droplat
proj4string(Dropoff_p) <- CRS("+init=epsg:4326")
proj4string(Dropoff_d) <- CRS("+init=epsg:4326")
map_p <- mapview(Dropoff_p, color = "red", col.regions = "red")
map_d <- mapview(Dropoff_d, color = "blue", col.regions = "blue")
map_p + map_d