【R语言编程绘图-折线图】
安装与加载GGPLOT2库
确保已安装ggplot2
库,若未安装可通过以下命令安装:
install.packages("ggplot2")
加载库:
library(ggplot2)
准备数据
假设有一个包含时间序列数据的数据框df
,包含两列:date
(日期)和value
(数值)。示例数据生成:
df <- data.frame(date = seq(as.Date("2023-01-01"), as.Date("2023-12-31"), by = "month"),value = c(15, 18, 22, 25, 30, 28, 26, 24, 20, 18, 16, 14)
)
基础折线图绘制
使用geom_line()
绘制折线图:
ggplot(df, aes(x = date, y = value)) +geom_line()
自定义折线图样式
调整线条颜色、粗细和添加点标记:
ggplot(df, aes(x = date, y = value)) +geom_line(color = "blue", linewidth = 1) +geom_point(color = "red", size = 3)
添加标题与坐标轴标签
通过labs()
函数设置标题和标签:
ggplot(df, aes(x = date, y = value)) +geom_line(color = "blue") +labs(title = "Monthly Value Trends (2023)",x = "Date",y = "Value")
调整坐标轴格式
例如将日期格式化为月份缩写:
ggplot(df, aes(x = date, y = value)) +geom_line(color = "blue") +scale_x_date(date_labels = "%b") +labs(title = "Monthly Trends", x = "Month", y = "Value")
多系列折线图
若数据包含分组(如category
列),可通过aes(color)
区分不同系列:
df_multi <- data.frame(date = rep(seq(as.Date("2023-01-01"), as.Date("2023-06-01"), by = "month"), 2),value = c(15, 18, 22, 25, 30, 28, 10, 12, 15, 18, 20, 22),category = rep(c("A", "B"), each = 6)
)ggplot(df_multi, aes(x = date, y = value, color = category)) +geom_line() +labs(title = "Multi-Series Line Chart")
# 加载必要的库
library(ggplot2)# 生成数据
df <- data.frame(date = seq(as.Date("2023-01-01"), by = "day", length.out = 100),value = cumsum(rnorm(100))
)# 绘制折线图
p <- ggplot(df, aes(x = date, y = value)) +geom_line(color = "blue", size = 1) + # 使用蓝色线条,适当调整线条粗细labs(title = "Time Series Plot of Random Values", # 标题x = "Date", # X轴标签y = "Cumulative Sum of Random Values") + # Y轴标签theme_classic() + # 使用经典主题theme(plot.title = element_text(size = 16, face = "bold", hjust = 0.5), # 标题样式axis.title = element_text(size = 14, face = "bold"), # 轴标题样式axis.text = element_text(size = 12), # 轴刻度标签样式legend.position = "none") # 移除图例(如果不需要)# 保存为高分辨率图像
ggsave("time_series_plot.png", plot = p, width = 8, height = 6, dpi = 300)# 显示图像
print(p)