色と形に基づいたRのリーフレットの凡例

Question

私は、データフレーム内のいくつかの変数に基づいて色と形が異なるリーフレットプロット上にアイコンを持っています。私は、それぞれの図形と色の組み合わせが何を表しているかを示すプロットに凡例を含めたいと思います。私はどうすればいいのですか？ base64encを使用して、固定ファイル名を作成する代わりにtempfileを使用して、this postに基づい

library(leaflet) 

lat1= 36+runif(n=5,min=-1,max=1) 

lon1 =-115+runif(n=5,min=-1,max=1) 

lat2= 35+runif(n=5,min=-0.5,max=0.5) 
lon2 =-110+runif(n=5,min=-0.5,max=0.5) 

lat3= 34+runif(n=5,min=-0.5,max=0.5) 
lon3 =-112+runif(n=5,min=-0.5,max=0.5) 
data_all=rbind(data.frame(Longitude=lon1,Latitude=lat1,Group=sample(c(16,17,18),5,replace = TRUE),condition=sample(c("red","blue","green"),5,replace = TRUE),stringsAsFactors = FALSE), 
      data.frame(Longitude=lon2,Latitude=lat1,Group=sample(c(16,17,18),5,replace = TRUE),condition=sample(c("red","blue","green"),5,replace = TRUE),stringsAsFactors = FALSE), 
      data.frame(Longitude=lon3,Latitude=lat1,Group=sample(c(16,17,18),5,replace = TRUE),condition=sample(c("red","blue","green"),5,replace = TRUE),stringsAsFactors = FALSE)) 

# A function to create png images for each shape and color 
pchIcons = function(pch = 1, width = 30, height = 30, bg = "transparent", col = NULL, ...) { 
    n = length(pch) 
    files = character(n) 
    # create a sequence of png images 
    for (i in seq_len(n)) { 
    f = tempfile(fileext = '.png') 
    png(f, width = width, height = height, bg = bg) 
    par(mar = c(0, 0, 0, 0)) 
    plot.new() 
    points(.5, .5, pch = pch[i], col = col[i], cex = min(width, height)/8, ...) 
    dev.off() 
    files[i] = f 
    } 
    files 
} 
### --------- 


leaflet(data_all)%>% addTiles() %>% 
    addMarkers(
    data = data_all, 
    icon = ~ icons(
     iconUrl = pchIcons(pch= Group,width=40,height=40,col=condition,lwd=4), 
     popupAnchorX = 20, popupAnchorY = 0 
    )) 

Answer 1

：

# A function to create file names 
filename <- function(pch,col) paste0(pch, '_', col, '.png') 

# A function to create png images for each shape and color 
pchIcons = function(pch = 1, width = 30, height = 30, bg = "transparent", col = NULL, ...) { 
    n = length(pch) 
    files = character(n) 
    # create a sequence of png images 
    for (i in seq_len(n)) { 
    f = filename(pch[i], col[i]) 
    png(f, width = width, height = height, bg = bg) 
    par(mar = c(0, 0, 0, 0)) 
    plot.new() 
    points(.5, .5, pch = pch[i], col = col[i], cex = min(width, height)/8, ...) 
    dev.off() 
    files[i] = f 
    } 
    files 
} 

# A function to build the legend 
build_legend <- function(){ 
    paste(sapply(strsplit(unique(paste(data_all$Group,data_all$condition)), " "), 
       function(x){ 
       paste0("<img src='data:image/png;base64,", 
         base64enc::base64encode(filename(x[[1]], x[[2]])), 
         "' width='16'; height='16'> ", 
         "Group=",x[[1]], " Condition=", x[[2]], 
         "<br/>")}), collapse = " ") 
} 

# The plot 
leaflet(data_all)%>% addTiles() %>% 
    addMarkers(
    data = data_all, 
    icon = ~ icons(
     iconUrl = pchIcons(pch= Group,width=40,height=40,col=condition,lwd=4), 
     popupAnchorX = 20, popupAnchorY = 0)) %>% 
    addControl(html = build_legend(), position = "bottomleft") 

ダミーデータを実証するために