R數據可視化手冊學習簡單的繪製常見的圖形

1.繪製散點圖

# 使用ggplot2
library(ggplot2)
ggplot(data = mtcars, aes(x = wt, y = mpg)) + geom_point()

 

2.繪製折線圖

# 使用ggplot
library(ggplot2)
# 繪製第一條折線附有數據點
g <- ggplot(data = pressure, aes(x = temperature, y = pressure)) +
  geom_line(color = "blue") +
  geom_point(color = "blue")


g + # 繪製第二條折線附有數據點
  geom_line(data = pressure, aes(temperature, pressure/2), color = "red") +
  geom_point(data = pressure, aes(temperature, pressure/2), color = "red")

 

3.繪製條形圖

 

# 使用ggplot2(左圖)
library(ggplot2)
g <- ggplot(data = BOD, aes(x = Time, y = demand)) +
  geom_bar(stat = "identity")

# 調用
g

# ===========================================================

# 使用factor是爲了離散x軸取值,這樣沒有多餘的間隔（右圖）
library(ggplot2)
g <- ggplot(data = BOD, aes(x = factor(Time), y = demand)) +
  geom_bar(stat = "identity")

# 調用
g

 

4.繪製直方圖 

# 繪製直方圖 "+" 運算經過賦值在調用
library(ggplot2)
g <- ggplot(data = mtcars, aes(x = mpg)) + 
  geom_histogram(binwidth = 4)

# 調用
g

 

5.繪製函數圖

# 使用ggplot2
# 設置函數
myFun <- function(x){
  1/x
}

g <- ggplot(data = data.frame(x = c(0, 20)), aes(x = x)) +
  stat_function(fun = myFun, geom = "line", col = "red") # col設置顏色

# 調用
g