Adding a Legend in ggplot with multiple datasets

Question

I am trying to combine multiple datasets into one figure in r. My code doesn't seem to be generating a legend for this data.

My two questions are:

1. Can I add some code expression into my lines to generate a legend element for each set of data? I thought this would be a command such as 'fill' or 'shape' - but I am wrong
2. Is there a reason why I am not g generating a legend full stop? I was expecting at least a legend with one set of data - but it appears with none - is one deconflicting with another?

If the above cannot be done, then is there a straightforward way to plot this figure using a 3 column data.table using the groupings of each data?

The code is below. You wont be able to reproduce it as I would need to send you the CSV files ( the datasets).

I have included the output figure from the code copied below. Idealy I would like a legend that lists a label for each different line/point +/- a text label at each line.

Thank you for any help!

library(tidyverse)
#These are the datasets I am turning into three dataframes #
bowen.data <- bowen
df <- data.frame(bowen)


lit.data <- lit_data
df <- data.frame(lit_data)

shock.data <- shock_tube_tests
df <- data.frame(shock_tube_tests)

high.data <- high_shock_data
df <- data.frame(high_shock_data)
low.data <- low_shock_data
df <- data.frame(low_shock_data)
#setting limit for my axis#
options(scipen = 1000000)



library(ggplot2)
#Now I wish to plot alll this data on one figure. This data describes duration and peak overpressure of shock waves. Each line of geom_line is trying to plot each datasset to produce each line, or points. I then set the X & Y limiitss, the labelss and the colours. #

ggplot(bowen.data, aes(x=Duration)) + 
  geom_line(aes(y = survival99), color = "cornflowerblue", linetype="longdash") + geom_line(aes(y = survival90), color="dodgerblue1", linetype="dashed") +
geom_line(aes(y = survival50), color="steelblue", linetype="solid") +
geom_line(aes(y = survival10), color="dodgerblue2", linetype="dotdash") +
geom_line(aes(y = survival1), color="dodgerblue3", linetype="twodash") + geom_line(aes(y = lung), color="darkslategrey", linetype="solid") +
ylim(100,1100000) + xlim(0.2,20) + ylab("Peak Overpressure") + xlab("Duration") +
geom_point(data=high.data, aes(x=duration, y=high), color='seagreen4') +
geom_point(data=low.data, aes(x=duration, y=low), color='indianred') +
geom_point(data=low.data, aes(x=duration, y=low), color='indianred', shape = 13) + 
geom_point(data=shock.data, aes(x=duration, y=tube), color='violetred4', shape = 17) +
geom_point(data=lit.data, aes(x=dura, y=lit), color='orange')

Using dput:

   structure(list(Duration = c(0.2, 0.3, 0.4, 0.5, 0.6), survival99 = c(3509982.865, 
2422907.195, 1883026.274, 1555445.788, 1348277.839), survival90 = c(4138911.806, 
2846984, 2206434.933, 1822870.548, 1566705.278), survival50 = c(5104973.144, 
3490782.825, 2693285.691, 2217270.161, 1900462.526), survival10 = c(6313217.275, 
4294375.461, 3299414.021, 2705203.586, 2313630.72), survival1 = c(7513231.158, 
5090961.551, 3899360.722, 3190981.429, 2711178.007), lung = c(1020994.629, 
698156.565, 538657.1381, 443454.0321, 380092.5051), X8 = c(NA, 
NA, NA, NA, NA)), row.names = c(NA, -5L), class = c("tbl_df", 
"tbl", "data.frame"))
[

shock data

    structure(list(duration = c(1.00244911, 0.947052916, 1.675566344, 
1.6586253, 1.837305476), tube = c(24973.80469, 28125.45703, 169033.3438, 
165488.6719, 285638.9375)), row.names = c(NA, -5L), class = c("tbl_df", 
"tbl", "data.frame"))

lit data

    
structure(list(dura = c(2, 6, 1.3, 6.9, 2), lit = c(1000000, 
1000000, 760000, 760000, 450000)), row.names = c(NA, -5L), class = c("tbl_df", 
"tbl", "data.frame"))
[ `enter image description here][1]

Answer 1

I don't see your desired output. The idea is to assign a colour to each line by mapping the colour aesthetic to a constant string. The simplest option is to select the string that will appear in the legend. It is critical that this is done within the aes call; you are creating a mapping to this variable.

These strings can now be mapped to the appropriate colours by scale color manual.

 library(ggplot2)
 library(tidyverse)
 library(ggthemes)

ggplot(bowen.data, aes(x=Duration)) + 
  geom_line(aes(y = survival99, color="survival99"),  linetype="longdash", size=2) + 
  geom_line(aes(y = survival90, color="survival90"),  linetype="dashed",  size=2) +
  geom_line(aes(y = survival50, color="survival50"),  linetype="solid",  size=2) +
  geom_line(aes(y = survival10, color="survival10"),  linetype="dotdash",  size=2) +
  geom_line(aes(y = survival1, color="survival1"),  linetype="twodash",  size=2) + 
  geom_line(aes(y = lung, color="Lung"), linetype="solid",  size=2) +
  ylim(100,1100000) + xlim(0.2,20) + ylab("Peak Overpressure") + xlab("Duration") +
  #geom_point(data=high.data, aes(x=duration, y=high), color='seagreen4') +
  #geom_point(data=low.data, aes(x=duration, y=low), color='indianred') +
  #geom_point(data=low.data, aes(x=duration, y=low), color='indianred', shape = 13) + 
  geom_point(data=shock.data, aes(x=duration, y=tube, color='shock.data'), shape = 17, size=3) +
  geom_point(data=lit.data, aes(x=dura, y=lit, color='lit.data'), size=3)+
  theme_pander()+
  theme(axis.text.x = element_text( hjust = 1, face="bold", size=12, color="black"), 
        axis.title.x = element_text(face="bold", size=16, color="black"),
        axis.text.y = element_text(face="bold", size=12, color="black"),
        axis.title.y = element_text(face="bold", size=16, color="black"),
        legend.title=element_blank(),
        legend.text = element_text(family="Times", color = "black", size = 16,face="bold"))+
  scale_color_manual(values = c("survival1"="dodgerblue3","survival10"="dodgerblue2",  "survival50"="steelblue", "survival90"="dodgerblue1", "survival99"="cornflowerblue", "lit.data"="orange","Lung"="darkslategrey","shock.data"="violetred4")) 
             

Plot:

Also you need to adjust the range of the ylim and xlim . Below ylim(0,6600000) + xlim(0.2, 8)

If you want to add labels to lines ( bowen.data ), I recommend using the using the directlabels library.

Sample code:

   library(dplyr)
   library(ggplot2)
   library(ggthemes)
   library(directlabels)


     bowen.data%>% 
  pivot_longer(cols = -1) %>%
  ggplot(aes(x=Duration,y=value))+
  geom_line(aes(linetype=name, color=name), size=2 )+
  scale_color_manual(values = c("lung"="darkslategrey", "survival1"="dodgerblue3","survival10"="dodgerblue2",  "survival50"="steelblue", "survival90"="dodgerblue1", "survival99"="cornflowerblue"))+ 
  scale_linetype_manual(values=c("lung"="solid","survival1" = "twodash", "survival10" = "dotdash", "survival50" = "solid" , "survival90" = "dashed", "survival99" = "longdash"))+
  geom_dl(aes(label = name), method = list(dl.trans(x = x + 0.2),"last.points", cex = 1.2, fontface='bold'))+
  ylim(0,6600000) + xlim(0.2, 8) + 
  labs(x="Duration",y="Peak Overpressure", fill="Factors") +
  theme_pander()+
  theme(axis.text.x = element_text( hjust = 1, face="bold", size=12, color="black"), 
        axis.title.x = element_text(face="bold", size=16, color="black"),
        axis.text.y = element_text(face="bold", size=12, color="black"),
        axis.title.y = element_text(face="bold", size=16, color="black"),
        legend.title=element_blank(),
        legend.text = element_text(family="Times", color = "black", size = 16,face="bold"))

Plot:

Sample data:

bowen.data <-
      structure(
        list(
          Duration = c(0.2, 0.3, 0.4, 0.5, 0.6),
          survival99 = c(
            3509982.865,
            2422907.195,
            1883026.274,
            1555445.788,
            1348277.839
          ),
          survival90 = c(4138911.806,
                         2846984, 2206434.933, 1822870.548, 1566705.278),
          survival50 = c(
            5104973.144,
            3490782.825,
            2693285.691,
            2217270.161,
            1900462.526
          ),
          survival10 = c(6313217.275,
                         4294375.461, 3299414.021, 2705203.586, 2313630.72),
          survival1 = c(
            7513231.158,
            5090961.551,
            3899360.722,
            3190981.429,
            2711178.007
          ),
          lung = c(1020994.629,
                   698156.565, 538657.1381, 443454.0321, 380092.5051),
          X8 = c(NA,
                 NA, NA, NA, NA)
        ),
        row.names = c(NA,-5L),
        class = c("tbl_df",
                  "tbl", "data.frame")
      )
    
    
    
    shock.data<-structure(
      list(
        duration = c(1.00244911, 0.947052916, 1.675566344,
                     1.6586253, 1.837305476),
        tube = c(
          24973.80469,
          28125.45703,
          169033.3438,
          165488.6719,
          285638.9375
        )
      ),
      row.names = c(NA,-5L),
      class = c("tbl_df",
                "tbl", "data.frame")
    )
    
    
    lit.data<-structure(
      list(
        dura = c(2, 6, 1.3, 6.9, 2),
        lit = c(1000000,
                1000000, 760000, 760000, 450000)
      ),
      row.names = c(NA,-5L),
      class = c("tbl_df",
                "tbl", "data.frame")
    )
    #These are the datasets I am turning into three dataframes #
    bowen.data <- bowen
    df <- data.frame(bowen)
    
    
    lit.data <- lit_data
    df <- data.frame(lit_data)
    
    shock.data <- shock_tube_tests
    df <- data.frame(shock_tube_tests)
    
    #high.data <- high_shock_data
    #df <- data.frame(high_shock_data)
    
    #low.data <- low_shock_data
    #df <- data.frame(low_shock_data)
    #setting limit for my axis#
    #options(scipen = 1000000)