Hide some legend entries in ggplot-CodePudding

I have the follow lines of code:

ggplot()   
  geom_line(data=TS_SimHeads_HOBS_final, aes(x=as.Date(Date), y=BH2672), color='red')   
  geom_point(data=Hydro_dates_wellData_2014_2018, aes(x=as.Date(Date), y=BH2672), color='red')  
  geom_line(data=TS_SimHeads_HOBS_final, aes(x=as.Date(Date), y=BH3025), color='green')   
  geom_point(data=Hydro_dates_wellData_2014_2018, aes(x=as.Date(Date), y=BH3025), color='green')  
  xlab("Date")   ylab("Head")
  #theme_bw()

which generate the following plot:

What I am trying to do, unsuccessfully, is to include legends only for the lines (points are the experimental data and lines the simulated ones). Some data for reproduction purposes:

Date BH2672 BH278 BH2978 BH2987 BH3025 BH312 BH3963 BH3962 BH3957
2014-02-19 31.28400 78.86755 5.671027 39.48419 53.60201 44.29516 69.23685 61.70843 56.13871
2014-02-20 30.76656 78.87344 5.656940 39.49012 53.56489 44.50679 69.50910 61.70638 56.09621
2014-02-21 30.43226 78.88097 5.642136 39.49902 53.56041 44.65761 69.65709 61.70126 56.04346
2014-02-22 30.16532 78.88979 5.643818 39.51101 53.56065 44.78333 69.75621 61.69643 55.99459
2014-02-23 29.93577 78.89954 5.650873 39.52544 53.55970 44.89429 69.82983 61.69332 55.95241
2014-02-24 29.73162 78.90991 5.658991 39.54147 53.55682 44.99520 69.88845 61.69236 55.91639

CodePudding user response：

As is quite often the case you first have to convert both of your datasets to long or tidy format using e.g. tidyr::pivot_longer which will result in a new column with the variable names as categories which could then be mapped on the color aes. Doing so will automatically create a legend and also allows to simplify your code. And if you want only the lines to appear in the legend then you could add show.legend=FALSE to geom_point. Finally you can set your desired colors via scale_color_manual.

As you provided only one dataset I used this for both datasets which however shouldn't matter. Also, to make my life a bit easier I have put the datasets in an named list:

library(dplyr, warn = FALSE)
library(tidyr)
library(ggplot2)

data_list <- list(data = Hydro_dates_wellData_2014_2018, sim = TS_SimHeads_HOBS_final) %>%
  lapply(function(x) {
      x %>%
      select(Date, BH2672, BH3025) %>%
      mutate(Date = as.Date(Date)) %>%
      tidyr::pivot_longer(-Date)
  })

ggplot()   
  geom_line(data=data_list$sim, aes(x=Date, y=value, color = name))  
  geom_point(data=data_list$data, aes(x=Date, y=value, color = name), show.legend = FALSE)  
  scale_color_manual(values = c(BH2672 = "red", BH3025 = "green"))  
  labs(x = "Date", y = "Head")

DATA

TS_SimHeads_HOBS_final <- structure(list(Date = c(
  "2014-02-19", "2014-02-20", "2014-02-21",
  "2014-02-22", "2014-02-23", "2014-02-24"
), BH2672 = c(
  31.284,
  30.76656, 30.43226, 30.16532, 29.93577, 29.73162
), BH278 = c(
  78.86755,
  78.87344, 78.88097, 78.88979, 78.89954, 78.90991
), BH2978 = c(
  5.671027,
  5.65694, 5.642136, 5.643818, 5.650873, 5.658991
), BH2987 = c(
  39.48419,
  39.49012, 39.49902, 39.51101, 39.52544, 39.54147
), BH3025 = c(
  53.60201,
  53.56489, 53.56041, 53.56065, 53.5597, 53.55682
), BH312 = c(
  44.29516,
  44.50679, 44.65761, 44.78333, 44.89429, 44.9952
), BH3963 = c(
  69.23685,
  69.5091, 69.65709, 69.75621, 69.82983, 69.88845
), BH3962 = c(
  61.70843,
  61.70638, 61.70126, 61.69643, 61.69332, 61.69236
), BH3957 = c(
  56.13871,
  56.09621, 56.04346, 55.99459, 55.95241, 55.91639
)), class = "data.frame", row.names = c(
  NA,
  -6L
))

Hydro_dates_wellData_2014_2018 <- TS_SimHeads_HOBS_final