在R中，如何将每月的刻度线添加到显示日期的x轴？

# 示例数据
date_data <- c("2022-01-01", "2022-01-05", "2022-02-10", "2022-03-15", "2022-04-20")
value_data <- c(10, 15, 20, 25, 30)

# 将日期数据转换为日期格式
date <- as.Date(date_data, format = "%Y-%m-%d")

# 创建绘图区域
plot(date, value_data, type = "l", xlab = "Date", ylab = "Value", xlim = c(min(date), max(date)), ylim = c(min(value_data), max(value_data)))

# 添加x轴刻度线
at <- seq(from = min(date), to = max(date), by = "month")
labels <- format(at, "%b")
axis(side = 1, at = at, labels = labels, tick = TRUE)

# 绘制数据线条
lines(date, value_data)