如何使用 facet_wrap 在 R 中绘制多个位置点？答案

【问题标题】：how to use facet_wrap to ggplot multiple location point in R?如何使用 facet_wrap 在 R 中绘制多个位置点？
【发布时间】：2021-03-05 13:22:55
【问题描述】：

我正在尝试使用facet_wrap 的ggplot 功能plot 多个位置数据。我在创建 legends 时遇到了麻烦（完全错过了 95% 的置信区间）。以下是我的代码，如果有任何建议，我将不胜感激。

library(ggplot2)
library(lubridate)

set.seed(123)

DF1 <- data.frame(Date = seq(as.Date("2001-01-01"), to = as.Date("2005-12-31"), by = "1 month"),
                  Ob = runif(60,1,5), L95 =runif(60, 0,4), U95 = runif(60,2,7), Sim = runif(60,1,5),
                  Loc = rep("Upstream", 60))

DF2 <- data.frame(Date = seq(as.Date("2001-01-01"), to = as.Date("2005-12-31"), by = "1 month"),
                  Ob = runif(60,1,5), L95 =runif(60, 0,4), U95 = runif(60,2,7), Sim = runif(60,1,5),
                  Loc = rep("Downstream", 60))

DF <- dplyr::bind_rows(DF1,DF2)

DF$Loc <- factor(DF$Loc, levels = c("Upstream","Downstream"))


ggplot(DF, aes(x = Date))+
  geom_ribbon(aes(ymin = L95, ymax = U95), fill = "grey30", alpha = 0.4)+
  geom_line(aes(y = Ob, color = "blue"), size = 1 )+
  geom_line(aes(y = Sim, color = "black"), size =  1, linetype = "dashed")+
  geom_vline(xintercept = as.Date("2004-12-01"),color = "red", size = 1.30)+
  facet_wrap(~ Loc, ncol = 1, scales = "free_y")+ 
  theme_bw()+
  scale_color_identity(guide = "legend", breaks = c("grey30", "blue", "black"),
                       labels = c("95% confidence bound", "Observation","Simulation"))

【问题讨论】：

标签： r dataframe ggplot2 plot lubridate

【解决方案1】：

您的填充在aes 函数之外，因此它不会出现在图例中。

ggplot(DF, aes(x = Date))+
  geom_ribbon(aes(ymin = L95, ymax = U95, color = "grey30"), fill = "grey30", alpha = 0.4)+
  geom_line(aes(y = Ob, color = "blue"), size = 1 )+
  geom_line(aes(y = Sim, color = "black"), size =  1, linetype = "dashed")+
  geom_vline(xintercept = as.Date("2004-12-01"),color = "red", size = 1.30)+
  facet_wrap(~ Loc, ncol = 1, scales = "free_y")+ 
  theme_bw()+
  scale_color_identity(guide = "legend", breaks = c("grey30", "blue", "black"),
                       labels = c("95% confidence bound", "Observation","Simulation"))

  ggplot(DF, aes(x = Date))+
    geom_ribbon(aes(ymin = L95, ymax = U95, fill = "grey30"), alpha = 0.4)+
    geom_line(aes(y = Ob, color = "blue"), size = 1 )+
    geom_line(aes(y = Sim, color = "black"), size =  1, linetype = "dashed")+
    geom_vline(xintercept = as.Date("2004-12-01"),color = "red", size = 1.30)+
    facet_wrap(~ Loc, ncol = 1, scales = "free_y")+ 
    theme_bw()+
    scale_color_identity(guide = "legend", breaks = c( "blue", "black"),
                         labels = c( "Observation","Simulation"),
                         name = 'Legend')+
    scale_fill_identity(guide = "legend", labels = c("95% confidence bound"), 
                        name=NULL)+
    theme(legend.spacing.y = unit(-0.2, "cm"))+
    theme(legend.title = element_text(margin=margin(b = 0.4, unit='cm')))

【讨论】：

我无法删除图例周围的框 - 我试过 theme(legend.key = element_rect(colour = NA, fill = NA), legend.box.background = element_blank()) 但它没有用 - 对此有什么想法吗？
不确定我是否理解！你在寻找类似stackoverflow.com/questions/49373461/… 的东西吗？
是的，但它在这里不起作用——不知道为什么？你能去掉图例周围的方框吗？
你说得对，这似乎不起作用。在答案中查看我的编辑
谢谢@Liman。有没有办法只在第一个方面添加注释？我试过annotate(geom = "Text", x = as.Date("2000-01-01"), y = 5, label = "Calibration")，但这在两个方面都添加了注释。

【解决方案2】：

我会这样做。

首先，您将 fill 用于功能区，而不是 color。其次，您需要将fill 实际映射到aes 中，而不仅仅是将其设置在aes 之外。然后我会在aes 调用中给出您想要的名称，并使用scale_*_manual 设置您想要的值：

ggplot(DF, aes(x = Date))+
  geom_ribbon(aes(ymin = L95, ymax = U95, fill = "95% confidence bound"), alpha = 0.4)+
  geom_line(aes(y = Ob, color = "Observation"), size = 1 )+
  geom_line(aes(y = Sim, color = "Simulation"), size =  1, linetype = "dashed")+
  geom_vline(xintercept = as.Date("2004-12-01"),color = "red", size = 1.30)+
  facet_wrap(~ Loc, ncol = 1, scales = "free_y")+ 
  theme_bw()+
  scale_color_manual(values = c('blue', 'black'), name = NULL) +
  scale_fill_manual(values = 'grey30', name = NULL)

有很多有效的方法可以解决这个问题，但有多少人这样做。

【讨论】：