How to specify ggplot legend order when you have multiple variables that are not all part of one col-CodePudding

I'm plotting the same data by different time scales (Week, Month, Quarter, etc.) using ggplot, and as a result, I'm pulling the data from different columns. However, when I see my legend, I want it to be a specific order.

I know if all the grouping variables were in one column, I could set it as an ordered factor, as it explained

CodePudding user response：

As @stefan mentioned right in the comments, you should set the names of your labels in the limits option of scale_colour_discrete. You can add more columns by yourself. You can use the following code:

library(dplyr)
library(ggplot2)
library(lubridate)

#Generates week data -- shouldn't be relevant to troubleshoot
by_week <- tibble(Week = seq(as.Date("2011-01-01"), as.Date("2012-07-01"), by="weeks"),
                  Week_score = c(sample(100:200, 79)),
                  Month = ymd(format(Week, "%Y-%m-01")))

#Generates month data -- shouldn't be relevant to troubleshoot                
by_month <- tibble(Month = seq(as.Date("2011-01-01"), as.Date("2012-07-01"), by="months"),
                   Month_score = c(sample(150:200, 19)))

#Joins data and removes duplications of month data for easier plotting -- shouldn't be relevant to troubleshoot  
all_time <- by_week %>%
  full_join(by_month) %>%
  mutate(helper = across(c(contains("Month")), ~paste(.))) %>% 
  mutate(across(c(contains("Month")), ~ifelse(duplicated(helper), NA, .)), .keep="unused") %>%
  mutate(Month = as.Date(Month))

#Makes plot - this is where I want the order in the legend to be different
all_time %>%
  ggplot(aes(x = Week))  
  geom_line(aes(y= Week_score, colour = "Week_score"))  
  geom_line(data=all_time[!is.na(all_time$Month_score),], aes(y = Month_score, colour = "Month_score"))   #This line tells R just to focus on non-missing values for Month_score
  scale_colour_discrete(labels = c("Week_score" = "Score - Week", "Month_score" = "Score - Month"), limits = c("Week_score", "Month_score"))

Output:

As you can see the order of the labels is changed.