花瓣图

花瓣图需要准备如下的文件

#读入作图文件，预处理，获取样本名称，统计共有元素个数等
flower_dat <- read.delim('flower.txt', header = T, sep = '\t', stringsAsFactors = F, check.names = F)
sample_id <- colnames(flower_dat)
otu_id <- unique(flower_dat[,1])
otu_id <- otu_id[otu_id != '']
core_otu_id <- otu_id
otu_num <- length(otu_id)

for (i in 2:ncol(flower_dat)) {
  otu_id <- unique(flower_dat[,i])
  otu_id <- otu_id[otu_id != '']
  core_otu_id <- intersect(core_otu_id, otu_id)
  otu_num <- c(otu_num, length(otu_id))}
core_num <- length(core_otu_id)

#下文中绘制椭圆的draw.ellipse()、draw.circle()等命令，需要plotrix包实现
library(plotrix)

#定义备选颜色（示例数据20个样本，所以我设置了20种颜色）
ellipse_col <- c('#6181BD4E','#F348004E','#64A10E4E','#9300264E','#464E044E','#049a0b4E','#4E0C664E','#D000004E','#FF6C004E','#FF00FF4E','#c7475b4E','#00F5FF4E','#BDA5004E','#A5CFED4E','#f0301c4E','#2B8BC34E')

#构建作图函数（参考自大神博客 https://www.cnblogs.com/xudongliang/p/7884667.html）
flower_plot <- function(sample, otu_num, core_otu, start, a, b, r, ellipse_col, circle_col) {
  par( bty = 'n', ann = F, xaxt = 'n', yaxt = 'n', mar = c(1,1,1,1))
  plot(c(0,10),c(0,10),type='n')
  n   <- length(sample)
  deg <- 360 / n
  res <- lapply(1:n, function(t){
    draw.ellipse(x = 5 + cos((start + deg * (t - 1)) * pi / 180),
                 y = 5 + sin((start + deg * (t - 1)) * pi / 180),
                 col = ellipse_col[t],
                 border = ellipse_col[t],
                 a = a, b = b, angle = deg * (t - 1))
    text(x = 5 + 2.5 * cos((start + deg * (t - 1)) * pi / 180),
         y = 5 + 2.5 * sin((start + deg * (t - 1)) * pi / 180),
         otu_num[t])
    
    if (deg * (t - 1) < 180 && deg * (t - 1) > 0 ) {
      text(x = 5 + 3.3 * cos((start + deg * (t - 1)) * pi / 180),
           y = 5 + 3.3 * sin((start + deg * (t - 1)) * pi / 180),
           sample[t],
           srt = deg * (t - 1) - start,
           adj = 1,
           cex = 1
      )
    } else {
      text(x = 5 + 3.3 * cos((start + deg * (t - 1)) * pi / 180),
           y = 5 + 3.3 * sin((start + deg * (t - 1)) * pi / 180),
           sample[t],
           srt = deg * (t - 1) + start,
           adj = 0,
           cex = 1
      )
    }           
  })
  draw.circle(x = 5, y = 5, r = r, col = circle_col, border = NA)
  text(x = 5, y = 5, paste('Core:', core_otu))
}

#调用上述函数作图，视情况修改参数
png('flower.png', width = 1500, height = 1500, res = 200, units = 'px')
flower_plot(sample = sample_id, otu_num = otu_num, core_otu = core_num,
            start = 90, a = 0.5, b = 2, r = 1, ellipse_col = ellipse_col, circle_col = '#00AAFFFF')
dev.off()
#注：参数a和b用于设置花瓣椭圆的尺寸，ellipse_col用于设置花瓣椭圆的颜色；参数r用于设置中心圆圈尺寸，circle_col用于设置中心圆圈的颜色