绘制大圆路径 [英] Plotting Great Circle Paths

问题描述

我试图绘制一些基于路径/连接的地图，但我无法弄清楚如何。

I'm trying to plot some path/connection based maps but am unable to figure out how.

我看到很多可能性的一个基于点的指标犯罪热点在伦敦等googleVis，ggmap等），但我找不到两个基于点的指标（城市之间的移民，火车路线等）太多的例子有一个例子与包 geosphere ，但它似乎不适用于 R 3.0.2 。

I see a lot of possibilities for one point based metrics (crime hotspots in London, etc. with googleVis, ggmap, etc.) but I can't find too many examples of two points based metrics (immigrations between cities, train routes, etc.) There is an example with the package geosphere, but it seems to not be available for R 3.0.2.

像这样 D3示例，也想自定义厚度，颜色等。

Ideally I would like something like this D3 example and would also like to customise the thickness, colour, etc. of the lines and the circles.

PS：我不认为 rCharts 可以做

PS: I don't suppose rCharts can do this just yet, right?

推荐答案

这是我去年开始的一个东西，从来没有正确抛光，但希望它应该回答你的问题

Here's something I started last year and never got around to polishing properly but hopefully it should answer your question of joining points on a map with great circle lines, with the flexibility to customise lines, circles etc.

我使用（我的）rworldmap软件包进行映射，WDI用于世界银行数据和地球圈为大圆线。目的是绘制从所有捐助国到所有受援国的援助流动（每个捐助者一个图）。下面是一个示例图，下面是代码。希望它有帮助。将很高兴找到时间再次接一个！
Andy

I use the (my) rworldmap package for mapping, WDI for world bank data and geosphere for the great circle lines. The aim was to plot aid flows from all donor countries to all recipient countries (one plot per donor). Below is an example plot, and below that the code. Hope it helps. Would be nice to find time to pick it up again! Andy

library(rworldmap)
library(WDI) # WORLD BANK INDICATORS

## lines of either type may obscure more than they add
##**choose line option here
addLines <- 'gc' #'none''straight' 'gc'
if ( addLines == 'gc' ) library(geosphere)

# setting background colours
oceanCol = rgb(7,0,30,maxColorValue=255) 
landCol = oceanCol 

#produces a list of indicator IDs and names as a matrix
indicatorList <- WDIsearch('aid flows')

#setting up a world map shaped plot window
#*beware this is windows specific
mapDevice('windows',width=10,height=4.5)


year <- 2000
#for(indNum in 1:2)
for(indNum in 1:nrow(indicatorList))
{
  indID <- indicatorList[indNum][1]
  donorISO3 <- substr(indID,start=8,stop=10)

  dFdonor <- WDI(indicator=indID,start=year,end=year)
  #divide by 10^6 for million dollars
  dFdonor[indID] <- dFdonor[indID] * 1/10^6

  sPDFdonor <- joinCountryData2Map(dFdonor,nameJoinColumn='country',joinCode='NAME')
  #take out Antarctica
  sPDFdonor <- sPDFdonor[-which(row.names(sPDFdonor)=='Antarctica'),]

  legendTitle=paste("aid flow from",donorISO3,year,"(millions US$)") 
  mapBubbles(sPDFdonor, nameZSize=indID, plotZeroVals=FALSE, legendHoriz=TRUE, legendPos="bottom", fill=FALSE, legendTitle=legendTitle, oceanCol=oceanCol, landCol=landCol,borderCol=rgb(50,50,50,maxColorValue=255),lwd=0.5,lwdSymbols=1)
  #removed because not working , main=paste('donor', donorISO3,year)

  #now can I plot lines from the centroid of the donor to the centroids of the recipients
  xDonor <- sPDFdonor$LON[ which(sPDFdonor$ISO3==donorISO3) ]
  yDonor <- sPDFdonor$LAT[ which(sPDFdonor$ISO3==donorISO3) ] 
  xRecips <- sPDFdonor$LON[ which(sPDFdonor[[indID]] > 0) ]
  yRecips <- sPDFdonor$LAT[ which(sPDFdonor[[indID]] > 0) ]
  amountRecips <- sPDFdonor[[indID]][ which(sPDFdonor[[indID]] > 0) ]


  ## straight lines
  if ( addLines == 'straight' )
  {
    for(line in 1:length(xRecips))
    {  
       #col <- 'blue'
       #i could modify the colour of the lines by the size of the donation
       #col=rgb(1,1,1,alpha=amountRecips[line]/max(amountRecips))
       #moving up lower values
       col=rgb(1,1,0,alpha=sqrt(amountRecips[line])/sqrt(max(amountRecips)))
       lines(x=c(xDonor,xRecips[line]),y=c(yDonor,yRecips[line]),col=col, lty="dotted", lwd=0.5)   #lty = "dashed", "dotted", "dotdash", "longdash", lwd some devices support <1
    }
  }

  ## great circle lines
  ## don't work well when donor not centred in the map
  ## also the loop fails at CEC & TOT because not ISO3 codes
  if ( addLines == 'gc' & donorISO3 != "CEC" & donorISO3 != "TOT" )
  {  
    for(line in 1:length(xRecips))
    {
      #gC <- gcIntermediate(c(xDonor,yDonor),c(xRecips[line],yRecips[line]), n=50, breakAtDateLine=TRUE)
      #30/10/13 lines command failed with Error in xy.coords(x, y) : 
      #'x' is a list, but does not have components 'x' and 'y'
      #adding sp=TRUE solved
      gC <- gcIntermediate(c(xDonor,yDonor),c(xRecips[line],yRecips[line]), n=50, breakAtDateLine=TRUE, sp=TRUE)

      #i could modify the colour of the lines by the size of the donation
      #col=rgb(1,1,1,alpha=amountRecips[line]/max(amountRecips))
      #moving up lower values
      col=rgb(1,1,0,alpha=sqrt(amountRecips[line])/sqrt(max(amountRecips)))

      lines(gC,col=col,lwd=0.5)
    }
  }  

  #adding coasts in blue looks nice but may distract
  data(coastsCoarse)
  plot(coastsCoarse,add=TRUE,col='blue')

  #repeating mapBubbles with add=T to go on top of the lines
  mapBubbles(sPDFdonor, nameZSize=indID, plotZeroVals=FALSE, fill=FALSE, addLegend=FALSE, add=TRUE, ,lwd=2)
  #removed because not working : , main=paste('donor', donorISO3,year)

  #looking at adding country labels
  text(xRecips,yRecips,sPDFdonor$NAME[ which(sPDFdonor[[indID]] > 0) ],col=rgb(1,1,1,alpha=0.3),cex=0.6,pos=4) #pos=4 right (1=b,2=l,3=ab)

  #add a title 
  nameDonor <- sPDFdonor$NAME[ which(sPDFdonor$ISO3==donorISO3) ]
  mtext(paste("Aid flow from",nameDonor,year), cex = 1.8, line=-0.8)

  #savePlot(paste("C:\\rProjects\\aidVisCompetition2012\\Rplots\\greatCircles\\wdiAidFlowLinesDonor",donorISO3,year,sep=''),type='png')
  #savePlot(paste("C:\\rProjects\\aidVisCompetition2012\\Rplots\\greatCircles\\wdiAidFlowLinesDonor",donorISO3,year,sep=''),type='pdf')

} #end of indNum loop

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