我可以看到两个选项如何在树梢上显示“灭绝”符号。
- 使用 Unicode 符号和可以按照this blog 显示的适当字体。
- 将光栅图像添加到树状图上。
以下代码将在树的绿色边缘旁边显示一个extinction symbol。它利用here 找到的信息。
library(jpeg)
logo <- readJPEG("Downloads/Symbol1.jpg")
logo2 <- as.raster(logo)
r <- nrow(logo2)/ncol(logo2) # aspect ratio
s <- 0.4 # symbol size
# display plot to obtain its size
plot(rec1, edge.color = c("black","black","black","black","darkgreen","black"),
edge.width = 2, edge.lty = c(rep(1,4),4,1))
lims <- par("usr") # plot area size
file_r <- (lims[2]-lims[1]) / (lims[4]-lims[3]) # aspect ratio for the file
file_s <- 480 # file size
# save tree with added symbol
png("tree_logo.png", height=file_s, width=file_s*file_r)
plot(rec1, show.tip.label = F,
edge.color = c("black","black","black","black","darkgreen","black"),
edge.width = 2, edge.lty = c(rep(1,4),4,1))
rasterImage(logo2, 1.6, 2.8, 1.6+s/r, 2.8+s)
# add axis
axisPhylo()
mtext(expression(Delta*italic("t")["i"]), side = 1, line = 3)
dev.off()