R可视化学习-- (8) 环形柱状图

柱状图可谓是论文最常见的图表了，但有时候这种笔直排列一排的柱状图用腻了， 换种呈现方式(比如拐个弯)也可换个心情嘛，今天就先来介绍俩种构建环形柱状图的方法，分别基于ggplot2和其他的R包来绘制。

数据创建处理

Category = paste0("category", "_", 1:9)
Percent <- c(81, 77, 70, 69, 69, 68, 62, 62, 61)
Result <-data.frame(Category,Percent)

# 设置各Categroy名称
Result$Category <-
  paste0(Result$Category," - ",Result$Percent,"%")

# 设置因子水平 
Result$Category <-
  factor(Result$Category, 
         levels=rev(Result$Category))

作图

ggplot(Result, aes(x = Category, y = Percent,
                               fill = Category)) + 
  geom_bar(width = 0.9, stat="identity") + 
  coord_polar(theta = "y") +
  xlab("") + ylab("") +
  ylim(c(0,100)) +
  ggtitle("Top 9 Categories") +
  geom_text(data = Result, hjust = 1, size = 3,
            aes(x = Category, y = 0, label = Category)) +
  theme_minimal() +
  theme(legend.position = "none",
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        axis.line = element_blank(),
        axis.text.y = element_blank(),
        axis.text.x = element_blank(),
        axis.ticks = element_blank())

image-20210123112038513

此时发现一个问题，环最中间的Category_9俨然已经变成了一个饼图形状了，都不能称之为柱状图了，所以如何将他变为空心呢？

很简单，我们增添一些数据即可~

len <- 4
df2 <- data.frame(Category = letters[1:len], Percent = rep(0, len), 
                  Category2 = rep("", len))
Result$Category2 <- Result$Category

# 合并数据
Result <- rbind(Result, df2)
Result$Category <-
  factor(Result$Category, 
         levels=rev(Result$Category))

ggplot(Result, aes(x = Category, y = Percent,
                               fill = Category2)) + 
  geom_bar(width = 0.9, stat="identity") + 
  coord_polar(theta = "y") +
  xlab("") + ylab("") +
  ylim(c(0,100)) +
  geom_text(data = Result, hjust = 1, size = 3,
            aes(x = Category, y = 0, label = Category2)) +
  theme_minimal() +
  theme(legend.position = "none",
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        axis.line = element_blank(),
        axis.text.y = element_blank(),
        axis.text.x = element_blank(),
        axis.ticks = element_blank())

image-20210123112758780

此时可以发现，内层的数据已经变成柱子形状，若感觉空心较大，调整len的个数即可控制了~~

其他方法—circlize包

Circlize包

circlize包可谓是做环状图神器，有时间会再深入学习这个包，因为发现该包的网址里也有类似的图形, 这里记录学习一下，有兴趣的可以去原网址学习下：https://jokergoo.github.io/circlize_book/book/ ，真的炒鸡详细，各类圈图应有尽有，只是代码不太ggplot，参数较多，额看你们自己了 ~~~

代码如下：

library(circlize)
color = rev(rainbow(length(Percent)))
circos.par("start.degree" = 90, cell.padding = c(0, 0, 0, 0))
circos.initialize("a", xlim = c(0, 100)) # 'a` just means there is one sector
circos.track(ylim = c(0.5, length(Percent)+0.5), track.height = 0.8, 
             bg.border = NA, panel.fun = function(x, y) {
               xlim = CELL_META$xlim
               
               circos.rect(rep(0, 9), 1:9 - 0.45, Percent, 1:9 + 0.45,
                           col = color, border = "white")
               circos.text(rep(xlim[1], 9), 1:9, 
                           paste(Category, " - ", Percent, "%"), 
                           facing = "downward", adj = c(1.05, 0.5), cex = 0.8) 
               breaks = seq(0, 85, by = 5)
               circos.axis(h = "top", major.at = breaks, labels = paste0(breaks, "%"), 
                           labels.cex = 0.6)
             })

image-20210123113021925

感觉比ggplot还好看一些，且外环添加上了百分比，细节满满，更多参数设置自己探索吧就~~