如何在ggplot中绘制多条线段

# 安装并加载ggplot2包
if (!require(ggplot2)) install.packages('ggplot2')
library(ggplot2)

# 示例数据框
df <- data.frame(
  time = rep(1:10, each = 3),
  value = c(runif(10), runif(10) + 1, runif(10) + 2),
  category = rep(c('A', 'B', 'C'), times = 10)
)

# 使用ggplot绘制多条线段
ggplot(df, aes(x = time, y = value, color = category)) +
  geom_line() +
  labs(title = 'Multiple Line Segments in ggplot2',
       x = 'Time',
       y = 'Value') +
  theme_minimal()

ggplot(df, aes(x = time, y = value, color = category, group = category)) +
  geom_line(alpha = 0.7) +
  labs(title = 'Multiple Line Segments with Transparency',
       x = 'Time',
       y = 'Value') +
  theme_minimal()