如何将 .csv 文件中的两个变量绘制为 ggplot2 中的两条线？

Question

我已导入一个 .csv 文件并将我的数据点绘制在折线图上。但我试图比较男性和女性的预期寿命，但我不知道如何为男性绘制一条线，为女性绘制一条线。

这是我的部分数据的示例（ALE 代表平均预期寿命）。

Year    Sex ALE
1900    Female  48.3
1900    Male    46.6
1901    Female  50.6
1901    Male    48
1902    Female  53.4
1902    Male    50.2
1903    Female  52
1903    Male    49.5
1904    Female  49.1
1904    Male    46.6
1905    Female  50.2
1905    Male    47.6

这是我到目前为止的代码。最终我会将我的工作放入一个 .rmd 文件中。

library(ggplot2) # call up ggplot2
library(RColorBrewer) # call up rcolorbrewer palette
options(scipen = 999) # remove scientific notation
sex <- read.csv("~/Big Data IBP/Life expectancy_sex.csv") # data focusing on life expectancy comparing sex. #male v. female
# run test to see how year of death has changed over the years
ggplot(data = sex, aes(x = Year, y = ALE)) +
  geom_line(linetype = "solid", col = "Blue", size = 0.5, arrow = arrow()) +
  labs(
    title = "Average Life Expectancy Based on Sex",
    subtitle = "1900-2014", x = "Year", y = "Age at Death"
  )

问题是我想要一条男性线和一条女性线来比较一张图表上的两条线。但我得到的实际结果是图上的一条线。

Answer 1

您需要将group、color 和linetype 映射到aes

library(ggplot2) # call up ggplot2
options(scipen = 999) # remove scientific notation

df <- read.table(text = "Year    Sex ALE
1900    Female  48.3
1900    Male    46.6
1901    Female  50.6
1901    Male    48
1902    Female  53.4
1902    Male    50.2
1903    Female  52
1903    Male    49.5
1904    Female  49.1
1904    Male    46.6
1905    Female  50.2
1905    Male    47.6",
                 header = TRUE, stringsAsFactors = FALSE)
# run test to see how year of death has changed over the years
ggplot(data = df, aes(x = Year, y = ALE, 
                      group = Sex, color = Sex, linetype = Sex)) +
  geom_line(size = 0.5, arrow = arrow()) +
  labs(
    title = "Average Life Expectancy Based on Sex",
    subtitle = "1900-2014", x = "Year", y = "Age at Death"
  ) +
  scale_color_brewer(palette = "Dark2") +
  theme_classic(base_size = 16)

^{由reprex package (v0.2.1) 于 2019 年 4 月 15 日创建}