r_programming : GGplot2

台大系統訓練班 r_programming 第3次期中作業 :

用一個 2x2 的畫布練習使用 ggplot2 繪製任意四個圖形

library(ggplot2)
library(gridExtra)
#-------------------------------------
gg1 <- ggplot(iris, aes(x = Petal.Length, colour = Species, fill = Species)) +
   geom_density(alpha = 0.65)
#-------------------------------------
gg2 <- ggplot(iris, aes(x = Sepal.Length, y = Sepal.Width, color = Species)) +
   geom_point() +
   ggtitle("Sepal.Length vs. Sepal.Width") +
   xlab("Sepal length") +
   ylab("Sepal width")+
   geom_smooth(method = "lm")
#-------------------------------------
qua_fun <- function(x){
   return(x**2)}

exp_fun <- function(x){
   return(exp(x))}

gg3_1 <- ggplot(data.frame(x = c(-3, 3.5)), aes(x))
gg3 <- gg3_1 + stat_function(fun = qua_fun, geom = "line", col = "blue") +
   stat_function(fun = exp_fun, geom = "line", col = "green")+
   geom_hline(yintercept = 0, lty = 2) +
   geom_vline(xintercept = 0, lty = 2)+
   labs(title = "Quadratic, Exponential Function")
#-------------------------------------
gg4 <- ggplot(iris, aes(x = Species, y = Sepal.Length, fill = Species)) +
   geom_boxplot()
#-------------------------------------
grid.arrange(gg1, gg2, gg3, gg4, nrow = 2, ncol = 2)

# 調整aes()的參數..scaled..
gg5 <- ggplot(iris, aes(x = Petal.Length, colour = Species, fill = Species, ..scaled..)) +
   geom_density(alpha = 0.65)
plot(gg5)