圍繞數據中心點繪製兩個圓圈

我有一個圍繞中心點的緯度數據框。拉通代表兩組。這些組以1或0表示。我可以圍繞中心點繪製不同的形狀和顏色，但是我希望顏色更清晰。我還想分別圍繞300米和600米兩點劃兩圈。我曾嘗試與圍繞數據中心點繪製兩個圓圈

Plot circle with a certain radius around point on a map in ggplot2

工作，但有沒有運氣

一個小樣本看起來像這樣

lat <- c(42.99052, 42.99085, 42.99046, 42.99081, 42.99197, 42.99122, 42.99154,42.99161, 42.99102, 42.99014, 42.98966, 42.99091, 42.99092, 42.99114 ,42.99000) 
lon <-c(78.69961, -78.69871, -78.69878, -78.69868, -78.69825, -78.69929, -78.69784, -78.69960, -78.69904, -78.69918, -78.69998, -78.69746, -78.70145, -78.70020, -78.70010) 
response <- c(0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1) 
data <- data.frame(lat, lon, response)

我的中心點是

(42.990707, -78.698899)

我得到我的沒有圓圈和不同顏色的地圖，像這樣

library(ggplot2) 
library(ggmap) 
library(viridis) 

#getting map 

mapgilbert <- get_map(location = c(lon = -78.698899 , lat=42.990707), zoom = 17, 
        maptype = "terrain", scale = 2) 

ggmap(mapgilbert) + 
    geom_point(data = data, aes(x = lon, y = lat, color = response , alpha = 1, fill = response), 
      size = 2, shape = response) + 
    guides(fill = FALSE, alpha = FALSE, size = FALSE) + 
    scale_color_viridis(begin = 0, end = .7)

任何幫助，將不勝感激。

來源

2017-10-20 mikeL

得到了解決，我建議您按照從您鏈接到的問題這樣的回答：https://stackoverflow.com/a/34187878/ 7446435您可能需要了解一些關於投影的內容，但它基本上是最簡單的方法，可以準確獲得您所需的內容。 – Jul

@ Mikel Arnaiz，你爲什麼要畫圈子？ ;-) –

我通過修改答案

Plot circle with a certain radius around point on a map in ggplot2

center_df<-data.frame(ID=c(1),lon=c(-78.698899),lat=c(42.990707)) 

make_circles <- function(centers, radius, nPoints = 500){ 
    # centers: the data frame of centers with ID 
    # radius: radius measured in kilometer 
    # 
    meanLat <- mean(centers$lat) 
    # length per longitude changes with lattitude, so need correction 
    radiusLon <- radius /111/cos(meanLat/57.3) 
    radiusLat <- radius/111 
    circleDF <- data.frame(ID = rep(centers$ID, each = nPoints)) 
    angle <- seq(0,2*pi,length.out = nPoints) 

    circleDF$lon <- unlist(lapply(centers$lon, function(x) x + radiusLon * cos(angle))) 
    circleDF$lat <- unlist(lapply(centers$lat, function(x) x + radiusLat * sin(angle))) 
    return(circleDF) 
} 



myCircles <- make_circles(center_df, 0.2) 
myCircles2 <- make_circles(center_df, 0.1) 
mapgilbert2<- get_map(location = c(lon = -78.70000 , lat=42.991107), zoom = 16, 
        maptype = "terrain", scale = 2) 

ggmap(mapgilbert2)+ 
geom_point(data = data, aes(x = lon, y = lat, fill=as.factor(exposure) , alpha = 1), size = 2, pch=21)+ 
guides(fill=FALSE, alpha=FALSE, size=guide_legend)+ 
scale_color_viridis(begin = 0, end = .7)+ 
geom_point(data=myCircles,aes(x=lon,y=lat), color='red')+ 
geom_point(data=myCircles2,aes(x=lon,y=lat), color='blue')+ 
scale_fill_manual(values=c("purple", "green"))

來源

2017-10-21 17:33:40 mikeL

圍繞數據中心點繪製兩個圓圈

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