R單張圖船方向

Question

我有關於船只/船的位置以及航行方向的信息。 我想將它們繪制在帶有自定義圖標的傳單地圖上，該圖標看起來像一艘船。 我發現glyphicons圖標中的"tags"圖標最合適。 這里有一些數據可以玩：

dput(head(x))
structure(list(boatName = c("Conti Benguela", "Sunny Bay", "Sunny Horizon", 
"FMT URLA", "Qi Xiang 22", "STI Solidarity"), lat = c(37.115365, 
38.4772017, 14.632, 56.80515, 51.31172, -2.2783283), lon = c(15.2682183, 
-8.7888783, -79.5806667, 7.601885, -143.5678933, 46.6328383), 
    cog = c("16", "331", "182", "21", "288", "72")), row.names = c(NA, 
6L), class = "data.frame")

cog表示地面上的路線，對於該路線，圖標轉化為旋轉角度。 我正在使用以下代碼來當前繪制船只的位置和根據船只轉向的方向旋轉：

shipIcon <- makeAwesomeIcon("tag",iconRotate = x$cog)
leaflet() %>% addTiles() %>% 
  addAwesomeMarkers(lng=x$lon,lat=x$lat,icon=shipIcon,popup = x$boatName)

但是，如您所見， makeAwesomeIcon向不需要的圖標添加了背景標記。 我看了一眼這個和這個與后者正是我想做的事情。 如何完成我的任務，即按照它在沒有標記背景的情況下轉向的方向旋轉顯示自定義船舶圖標？

Answer 1

概觀

要繪制圖標方向，我遵循三個步驟：

1. 為了將HTML圖標呈現到傳單地圖上，我將leaflet::makeAwesomeIcon()換成leaflet::makeIcon() 。

2. 為了啟用圖標旋轉，我存儲了leaflet.rotatedMarker.js文件的本地副本，並將此插件注冊 為Leaflet 對象 。

3. 最后，為了指定圖標應該旋轉多少度，我將cog變量放置在leaflet::addMarkers()的markerOptions()內的rotationAngle參數內。

注意：步驟2和步驟3是從答案和關於小冊子包裝中 SO問題圖標旋轉的注釋中進行的。 所有功勞歸於@rrs和@Ufos。

在執行任何操作之前，我運行了您的代碼並獲得了以下傳單地圖：

使用boat.icon ，圖標被旋轉了，但更難閱讀：

最終，我決定使用亮橙色的leaflet::addCircleMarkers()和向北箭頭圖標來顯示位置和旋轉角度：

碼

# load necessary packages
library( htmltools )
library( htmlwidgets )
library( leaflet )

# this is taken from: https://gist.github.com/jcheng5/c084a59717f18e947a17955007dc5f92
# "Leaflet.rotatedMarker" is taken from https://raw.githubusercontent.com/bbecquet/Leaflet.RotatedMarker/master/leaflet.rotatedMarker.js
rotatedMarker <- 
  htmlDependency( name = "Leaflet.rotatedMarker" # note: this .js file has to be copied and stored in your current working directory 
                  , version = "0.1.2"
                  , src = normalizePath( path = getwd() )
                  , script = "leaflet.rotatedMarker.js" )

# this is taken from: https://gist.github.com/jcheng5/c084a59717f18e947a17955007dc5f92
registerPlugin <- function(map, plugin) {
  map$dependencies <- c(map$dependencies, list(plugin))
  map
}

# store data
df <-
  structure(list(boatName = c("Conti Benguela", "Sunny Bay", "Sunny Horizon", 
                              "FMT URLA", "Qi Xiang 22", "STI Solidarity"), lat = c(37.115365, 
                                                                                    38.4772017, 14.632, 56.80515, 51.31172, -2.2783283), lon = c(15.2682183, 
                                                                                                                                                 -8.7888783, -79.5806667, 7.601885, -143.5678933, 46.6328383), 
                 cog = c("16", "331", "182", "21", "288", "72")), row.names = c(NA, 
                                                                                6L), class = "data.frame")

# store boat png
boat.file <- "http://cdn.onlinewebfonts.com/svg/download_498189.png"

# store north arrow png
north.arrow.file <- "https://upload.wikimedia.org/wikipedia/commons/a/aa/Aiga_uparrow.svg"

# make boat icon
boat.icon <- 
  makeIcon( iconUrl = boat.file
            , iconWidth = 25
            , iconHeight = 25 )

# make north arrow icon
north.arrow.icon <-
  makeIcon( iconUrl = north.arrow.file
            , iconWidth = 10
            , iconHeight = 10 )

# display leaflet map
leaflet( data = df ) %>%
  addProviderTiles( provider = "OpenStreetMap.BlackAndWhite" ) %>%
  registerPlugin( plugin = rotatedMarker ) %>%
  addCircleMarkers( lng = ~lon
                    , lat = ~lat
                    , radius = 5
                    , fillColor = "orange"
                    , fillOpacity = 1
                    , stroke = FALSE ) %>%
  addMarkers( lng = ~lon
              , lat = ~lat
              , label = ~boatName
              , icon = north.arrow.icon
              , options = markerOptions( rotationAngle = ~cog ) )

# end of script #

會議信息

R version 3.4.4 (2018-03-15)
Platform: x86_64-apple-darwin15.6.0 (64-bit)
Running under: macOS High Sierra 10.13.2

Matrix products: default
BLAS: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/3.4/Resources/lib/libRlapack.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods  
[7] base     

other attached packages:
[1] leaflet_1.1.0.9000 htmlwidgets_1.0    htmltools_0.3.6   

loaded via a namespace (and not attached):
 [1] shiny_1.0.5     compiler_3.4.4  magrittr_1.5   
 [4] R6_2.2.2        markdown_0.8    tools_3.4.4    
 [7] yaml_2.1.18     Rcpp_0.12.16    crosstalk_1.0.0
[10] jsonlite_1.5    digest_0.6.15   xtable_1.8-2   
[13] httpuv_1.3.6.2  mime_0.5