Question

我希望使用ggplot2和地图在美国地图上绘制一组有限的埃博拉病毒数据。

参数是State和Ebola Infected（是/否）

含有该病毒的国家如下：

Texas Yes
Newyork Yes

这些州将以红色着色，而该国的其他州将采用绿色。

我不确定如何对此进行编码，我们将不胜感激。

下面是我可以使用stackoverflow上的其他线程构建的代码

library(ggplot2);
library(maps);
library(plyr);
library(mapproj);
ebolad = read.csv('/usa.csv');
#a data set including the state name and whether it is effected or not (yes/no)
colClasses = c('character', 'character', 'numeric')[[2]];
names(ebolad) = c('col', 'region', 'infected');
ebolad$region  = tolower(ebolad$region);
us_state_map = map_data('state');
map_data = merge(ebolad, us_state_map, by = 'region'); 
map_data = arrange(map_data, order);
ggplot(map_data, aes(x = long, y = lat, group = group)) +
  geom_polygon(aes(fill=infected)) +
  geom_path(colour = 'gray', linestyle = 2) +
  scale_fill_brewer('States affected with EBOLA Virus in USA', palette = 'PuRd') +
  coord_map();

有人可以帮我改善情节

Answer 1

请尝试使用fill的手动缩放。这是由

替换scale_fill_brewer(...)

scale_fill_manual('States affected with EBOLA Virus in USA', values=c("green","red"))

但是，这并没有给出最漂亮的绿色和红色。但您可以使用十六进制代码来定义任意颜色，例如values=c("#4daf4a","#e41a1c")。

infected的哪个值为红色取决于数据的详细信息。如果未感染状态应为绿色，只需使用values=c("red","green")切换颜色。

如果您的问题与文件usa.csv有关，则在没有该文件的情况下很难提供帮助。我通过以下命令生成数据：

ebolad<-data.frame(region=state.name,infected="no",stringsAsFactors=FALSE)
ebolad[ebolad$region %in% c("Texas","New York"),"infected"] <- "yes"

然后，使用前面提到的更改的代码，我得到了一个不错的情节。

Answer 2

  #Code to map USA states affected with Ebola Virus
    #import the following libraries
    library(ggplot2);
    library(maps);
    library(plyr);
    #begin of code
    # read the csv file containing the ebola data for usa (important: replace the directory path)
    ebolad = read.csv('usa.csv');
    colClasses = c('character', 'character', 'numeric')[[2]];
    names(ebolad) = c('col', 'region', 'infected');
    ebolad$region  = tolower(ebolad$region);
    # import the usa state data into local dataset
    us_state_map = map_data('state');
    # merge ebola data set and usa maps data set
    map_data = merge(ebolad, us_state_map, by = 'region'); 
    map_data = arrange(map_data, order);
    # storing the data of abbreviated state names to display on the final map
    states <- data.frame(state.center, state.abb)
    # code to plot the map with state names and colors to distinguish the infected states vs uninfected states
    ggplot(map_data, aes(x = long, y = lat, group = group)) +
    geom_polygon(aes(fill=infected)) +
    geom_path(colour = 'gray', linestyle = 2) +
    xlab("Longitude") + ylab("Latitude") +
    geom_text(data = states, aes(x = x, y = y, label = state.abb, group = NULL), size = 4)+
    scale_fill_manual('States affected with EBOLA Virus in USA', values=c("green4","red3")) +
    coord_map(project="globular") +
    theme_grey();
    #end of code

在美国地图上绘制疾病图

2 个答案: