ggplot2 增添数据 图上添加信息 时间线背景分区

向原有线中增添数据，加入人的信息

 

(unemp <- qplot(date, unemploy, data=economics, geom="line", 
  xlab = "", ylab = "No. unemployed (1000s)"))  ## 基础图层

presidential <- presidential[-(1:3), ] ##只保存总统名字和任期时间

yrng <- range(economics$unemploy) ##获取范围，会得到最大值和最小值
xrng <- range(economics$date)

unemp + geom_vline(aes(xintercept = as.numeric(start)), data = presidential) ##增加辅助线

unemp + geom_rect(aes(NULL, NULL, xmin = start, xmax = end, 
  fill = party), ymin = yrng[1], ymax = yrng[2], 
  data = presidential) + scale_fill_manual(values = 
  alpha(c("blue", "red"), 0.2))  ##采用party进行背景填充，xy为null

last_plot() + geom_text(aes(x = start, y = yrng[1], label = name), 
  data = presidential, size = 3, hjust = 0, vjust = 0)

caption <- paste(strwrap("Unemployment rates in the US have 
  varied a lot over the years", 40), collapse="\n")##以空格连接

unemp + geom_text(aes(x, y, label = caption), 
  data = data.frame(x = xrng[2], y = yrng[2]), 
  hjust = 1, vjust = 1, size = 4) ##放入对应的位置


Reference lines: horizontal, vertical, and diagonal
geom_abline(mapping = NULL, data = NULL, ..., slope, intercept,
  na.rm = FALSE, show.legend = NA)

geom_hline(mapping = NULL, data = NULL, ..., yintercept, na.rm = FALSE,
  show.legend = NA)

geom_vline(mapping = NULL, data = NULL, ..., xintercept, na.rm = FALSE,
  show.legend = NA)



Rectangles

Description

geom_rect and geom_tile do the same thing, but are parameterised differently: geom_rect uses the locations of the four corners (xmin, xmax, ymin and ymax), while geom_tile uses the center of the tile and its size (x, y, width, height). geom_raster is a high performance special case for when all the tiles are the same size.

Usage

geom_raster(mapping = NULL, data = NULL, stat = "identity",
  position = "identity", ..., hjust = 0.5, vjust = 0.5,
  interpolate = FALSE, na.rm = FALSE, show.legend = NA,
  inherit.aes = TRUE)

geom_rect(mapping = NULL, data = NULL, stat = "identity",
  position = "identity", ..., na.rm = FALSE, show.legend = NA,
  inherit.aes = TRUE)

geom_tile(mapping = NULL, data = NULL, stat = "identity",
  position = "identity", ..., na.rm = FALSE, show.legend = NA,
  inherit.aes = TRUE)