How do I add a line of best fit for scatterplot with multiple variables in ggplot-CodePudding

My data looks like this:

Male_0602 <- rnorm(N)
Female_0602 <- rnorm(N)
tce <- rnorm(N)

data <- data.frame(Male_0602, Female_0602, tce)

Currently, my code looks like this:

ggplot(data, aes(x = tce*100))   
  geom_point(aes(y = Male_0602, colour = "Male"))  
  geom_point(aes(y = Female_0602, colour = "Female"))  
  labs(x = "Province-level tariff cut",
       y = "Change in province-level wage between 2001 and 2005")

My scatterplot currently looks like this:

I would like to add a separate line of best fit for Male and Female. Can you please tell me how to do that? Thank you.

CodePudding user response：

Convert the data frame into long format and add geom_smooth().

library(tidyr)

data %>% 
  pivot_longer(cols = c(Male_0602, Female_0602), names_to = "gender") %>% 
  ggplot(aes(x = tce*100, y = value, color = gender))  
  geom_point()  
  geom_smooth(method = "lm", se = FALSE)  
  labs(x = "Province-level tariff cut",
       y = "Change in province-level wage between 2001 and 2005")

CodePudding user response：

The following code converts the data frame into a longer format so that the variables can be plotted on one geom, them use geom_smooth to add the best lit lines.

   data %>% 
      pivot_longer(cols = c(Male_0602, Female_0602), names_to = "cats") %>% 
      ggplot(aes(x = tce*100, y = value, colour = as_factor(cats))) 
      geom_point() 
      geom_smooth(method = "lm", se = FALSE)