在R中为不同ccy生成多折线图网格的实现方案咨询

给定如下R数据框样本：

structure(list(Series = c("A", "B", "A", "B", "A", "B", "A", 
"B", "A", "B", "A", "B", "A", "B", "A", "B", "A", "B", "A", "B"
), date = structure(c(19415, 19415, 19415, 19415, 19415, 19415,
19415, 19415, 19415, 19415, 19416, 19416, 19416, 19416, 19416,
19416, 19416, 19416, 19416, 19416), class = "Date"), ccy = c("CHF",
"CHF", "EUR", "EUR", "GBP", "GBP", "JPY", "JPY", "USD", "USD",
"CHF", "CHF", "EUR", "EUR", "GBP", "GBP", "JPY", "JPY", "USD",
"USD"), exp = c(-25.0260386883321, -13.4876728854438, 29.9242170197296,
28.1863060040971, -21.1816468152161, -17.6427844100702, -125.811601419233, 
-116.187338952966, -1574.53746806177, -944.410592575117, 13.687475030189,
5.55257290367663, 22.1373554559174, 9.839306286417, 9.60824459042358,
8.43043547492962, 75.9856738242059, 19.8785641759769, -2531.47779912341,
-313.689149325403)), row.names = c(NA, 20L), class = "data.frame")

需求：为ccy列每个唯一值生成折线图，每个图包含Series的A、B两个系列，横轴为date，纵轴为exp；所有图表格式统一，两个系列用不同颜色线条，标题标注对应ccy值，最终输出方形折线图网格。

使用ggplot2配合facet_wrap是最简洁高效的方案，能自动按ccy分面生成网格图，同时保证所有子图格式统一。

完整代码 #

# 加载tidyverse包（包含ggplot2和数据处理工具）
library(tidyverse)

# 假设数据框名为df（替换为你的实际变量名）
df <- structure(list(Series = c("A", "B", "A", "B", "A", "B", "A", 
"B", "A", "B", "A", "B", "A", "B", "A", "B", "A", "B", "A", "B"
), date = structure(c(19415, 19415, 19415, 19415, 19415, 19415,
19415, 19415, 19415, 19415, 19416, 19416, 19416, 19416, 19416,
19416, 19416, 19416, 19416, 19416), class = "Date"), ccy = c("CHF",
"CHF", "EUR", "EUR", "GBP", "GBP", "JPY", "JPY", "USD", "USD",
"CHF", "CHF", "EUR", "EUR", "GBP", "GBP", "JPY", "JPY", "USD",
"USD"), exp = c(-25.0260386883321, -13.4876728854438, 29.9242170197296,
28.1863060040971, -21.1816468152161, -17.6427844100702, -125.811601419233, 
-116.187338952966, -1574.53746806177, -944.410592575117, 13.687475030189,
5.55257290367663, 22.1373554559174, 9.839306286417, 9.60824459042358,
8.43043547492962, 75.9856738242059, 19.8785641759769, -2531.47779912341,
-313.689149325403)), row.names = c(NA, 20L), class = "data.frame")

# 绘制分面折线图
ggplot(df, aes(x = date, y = exp, color = Series)) +
  geom_line(linewidth = 1) +  # 设置线条粗细，提升可读性
  facet_wrap(~ccy, ncol = 2) +  # 按ccy分面，ncol控制网格列数（可按需调整）
  labs(x = "日期", y = "exp值", color = "系列") +  # 设置坐标轴和图例标题
  theme_bw() +  # 使用简洁的黑白基础主题
  theme(
    aspect.ratio = 1,  # 强制子图为方形
    strip.text = element_text(size = 12, face = "bold")  # 分面标题（ccy值）加粗放大
  ) +
  scale_color_manual(values = c("A" = "#2E86AB", "B" = "#F24C4E"))  # 自定义A、B系列颜色

关键说明 #

• facet_wrap(~ccy)：自动为每个ccy生成独立子图，ncol参数可根据ccy数量调整网格列数（比如设为2或3）。
• aspect.ratio = 1：严格保证每个子图为方形，满足需求。
• scale_color_manual：统一设置A、B系列的颜色，确保所有子图格式一致。
• theme_bw()：提供干净的基础样式，减少冗余元素，便于后续格式微调。

内容的提问来源于stack exchange，提问作者SuavestArt