ggplot绘制按Recorte列分三类着色的折线图相关问题求助

• 映射参数写错：ggplot的美学映射中，指定按字段分类着色需要用color参数，你写的factor不是合法的映射参数，不会生效
• 硬编码颜色优先级更高：你在geom_line()参数里直接写了color = "Purple"，这个固定赋值会覆盖aes()内的动态映射规则，所以颜色不会随Recorte字段变化

如果你要保留单条折线的连续性，仅按阶段切换颜色，需要额外加group = 1的映射（避免按颜色分组后折线断裂），示例代码如下：

library(ggplot2)
library(scales) # 你用到了date_format需要加载这个包

graflutudo <- ggplot(campanhalutudo, 
                     aes(x = `Hora da publicação`, 
                         y = Alcance, 
                         color = Recorte,
                         group = 1)) + 
  geom_line(linewidth = 1) + 
  # 保留原来的均值虚线
  geom_line(aes(y = mean(Alcance)), color = "red", linetype = "dotted", inherit.aes = FALSE) +
  # 可以自定义三个阶段的颜色，这里保留你原来的紫色作为其中一个
  scale_color_manual(values = c("Periodo 1" = "purple", "Periodo 2" = "orange", "Periodo 3" = "green")) +
  scale_y_continuous(breaks = seq(0, 85000, by = 10000)) +
  scale_x_datetime(labels = date_format("%m-%d"),
                   date_breaks = "4 days") +
  theme_light()

如果不想破坏折线本身的视觉连贯性，用不同颜色的半透明背景色块区分三个阶段会更直观，示例代码如下：

# 先提取每个阶段的时间范围
period_range <- aggregate(`Hora da publicação` ~ Recorte, data = campanhalutudo, FUN = range)
colnames(period_range) <- c("Recorte", "start", "end")

graflutudo <- ggplot(campanhalutudo, 
                     aes(x = `Hora da publicação`, 
                         y = Alcance)) + 
  # 先加背景色块，放在最底层
  geom_rect(data = period_range, 
            aes(xmin = start, xmax = end, 
                ymin = -Inf, ymax = Inf, 
                fill = Recorte),
            alpha = 0.2, inherit.aes = FALSE) +
  # 折线保持统一颜色
  geom_line(color = "purple", linewidth = 1) +
  geom_line(aes(y = mean(Alcance)), color = "red", linetype = "dotted") +
  # 自定义色块颜色
  scale_fill_manual(values = c("Periodo 1" = "purple", "Periodo 2" = "orange", "Periodo 3" = "green")) +
  scale_y_continuous(breaks = seq(0, 85000, by = 10000)) +
  scale_x_datetime(labels = date_format("%m-%d"),
                   date_breaks = "4 days") +
  theme_light()

内容的提问来源于stack exchange，提问作者Hayguneys