如何在R中创建填写了特定国家/地区的世界地图? [英] How to create a world map in R with specific countries filled in?

问题描述

我想用R生成非常基本的世界地图，其中用红色填充的一组特定国家/地区表明它们是疟疾流行国家/地区.

I would like to use R to generate a very basic world map with a specific set of countries filled with a red colour to indicate that they are malaria endemic countries.

我在数据框中列出了这些国家/地区，但正在努力将它们覆盖在世界地图上.

I have a list of these countries in a data frame but am struggling to overlay them on a world map.

我尝试使用wrld_simpl对象以及rworldmap软件包中的joinCountryData2Map方法.

I have tried using the wrld_simpl object and also the joinCountryData2Map method in the rworldmap package.

我会在这个答案上发表评论，以防止增加一个可能多余的问题，但是我目前没有足够的声誉，对此深表歉意.

I would comment on this answer to prevent addition of a possibly redundant question but I do not have enough reputation at the moment, apologies for this.

https://stackoverflow.com/a/9102797/1470099

我很难理解为plot()命令提供的参数-我想知道是否有一种简单的方法告诉R在wrld_simpl地图上的列表中标出列表中的所有国家/地区名称，而不是使用grepl()等.

I am having difficulty understanding the arguments given to the plot() command - I wondered if there was just an easy way to tell R to plot all of the country NAMEs in my list on the wrld_simpl map instead of using grepl() etc. etc.

plot(wrld_simpl, 
     col = c(gray(.80), "red")[grepl("^U", wrld_simpl@data$NAME) + 1])

推荐答案

使用rworldmap包，您可以使用以下代码:

Using the rworldmap package, you could use the following:

library(rworldmap)

theCountries <- c("DEU", "COD", "BFA")
# These are the ISO3 names of the countries you'd like to plot in red

malDF <- data.frame(country = c("DEU", "COD", "BFA"),
  malaria = c(1, 1, 1))
# malDF is a data.frame with the ISO3 country names plus a variable to
# merge to the map data

malMap <- joinCountryData2Map(malDF, joinCode = "ISO3",
  nameJoinColumn = "country")
# This will join your malDF data.frame to the country map data

mapCountryData(malMap, nameColumnToPlot="malaria", catMethod = "categorical",
  missingCountryCol = gray(.8))
# And this will plot it, with the trick that the color palette's first
# color is red

添加其他颜色并添加图片

Add other colors and include picture

## Create multiple color codes, with Burkina Faso in its own group
malDF <- data.frame(country = c("DEU", "COD", "BFA"),
  malaria = c(1, 1, 2))

## Re-merge
malMap <- joinCountryData2Map(malDF, joinCode = "ISO3",
  nameJoinColumn = "country")

## Specify the colourPalette argument
mapCountryData(malMap, nameColumnToPlot="malaria", catMethod = "categorical",
  missingCountryCol = gray(.8), colourPalette = c("red", "blue"))

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