R 在ggplot2中创建绘图（通过包）后更改图例中的跟踪名称

我想知道是否有任何简单的方法可以在一个ggplot创建后更改图例中的名称（使用颜色美学）。我知道这感觉有点粗糙，通常会在数据中或创建绘图时更改，但我想更改由另一个包创建的绘图上的标签，并且在该包中没有更改它的选项

很明显，我可以复制这个函数，保存我自己的版本并对其进行更改，但我只想更改一件事，这样看起来更整洁，如果我以后再做的话

这里是一个有一些虚拟数据的例子，基本上我想将fasstr的

绘图(每日)统计数据

中的平均值和中位数时间序列重新标记为“建模平均值”和“建模中位数”，这样它们就不会与我手动添加的观察平均值混淆

    library(fasstr)
    library(tibble)
    library(ggplot2)

    #create some fake data
    df <- tibble(Date = seq.Date(from = as.Date("1991-01-01"), as.Date("1997-12-31"), 
                                      by = "day"),
                     DayOfYear = as.numeric(format(Date, "%j")),
                     Value = runif(2557,0,1) + 50 + (cos((1/60)*DayOfYear)+4))

    obsdf <- tibble(Date = seq.Date(from = as.Date("1900-01-01"), as.Date("1900-12-31"), 
                            by = "day"),
                 DayOfYear = as.numeric(format(Date, "%j")),
                 Value = runif(365,0,1) + 51 + (cos((1/60)*DayOfYear)+4))



    # create plot using fasstr package
    plt1<- fasstr::plot_daily_stats(df)

    # add my own trace. I also want to rename the trace "Mean" to 
     # "Modelled Mean" to avoid confusion (and same with Median) 
    plt1$Daily_Statistics +
      geom_line(data = obsdf, aes(x = Date, y = Value, colour = "Observed Mean"))+
      scale_colour_manual(values = c("red", "black","blue"))

---

无需黑客攻击，只需将标签添加到手动秤上即可

plt1$Daily_Statistics +
  geom_line(data = obsdf, aes(x = Date, y = Value, colour = "Observed Mean"))+
  scale_colour_manual(labels = c("Modelled Mean","Modelled Median","Observed Mean"),
                      values = c("red", "black","blue"))

---

没问题。一开始我也没想到。

plt1$Daily_Statistics +
  geom_line(data = obsdf, aes(x = Date, y = Value, colour = "Observed Mean"))+
  scale_colour_manual(labels = c("Modelled Mean","Modelled Median","Observed Mean"),
                      values = c("red", "black","blue"))