Change order of dates in R ggplot?-CodePudding

I have been working on a plot in R using ggplot and plotting dates on the x axis. I have noticed that R does not recognize them as dates, and so the order on the x axis is wrong. I have tried many different things such as using as.Date(), manually editing levels and ordering the x axis, but nothing has worked. Here's my code:

library(dplyr)
library(ggplot2)
library(hrbrthemes)

calories_data = read.csv('dailyCalories_clean.csv',header = TRUE, sep=",")

ggplot(calories_data, aes(x= ActivityDay, y=Calories, group=Id, color = Id)) 
  geom_line()

Here's the plot

I appreciate any help, I'm new at this and have been researching for hours with no success. Thank you!

CodePudding user response：

One option to fix your issue would be to convert your dates to proper dates to fix the order and use the date_labels argument of scale_x_date to format your dates. To convert to dates you have to add a fake year to your ActivityDay, e.g. "2022":

Using some fake random data to mimic your real data:

library(ggplot2)

set.seed(123)

calories_data <- data.frame(
  ActivityDay <- rep(c("4/1", "4/10", "5/11", "5/1"), 3),
  Id = rep(1:3, each = 4),
  Calories = runif(12, 1000, 3000)
)

calories_data$ActivityDay <- as.Date(paste("2022", calories_data$ActivityDay, sep = "/"), format = "%Y/%m/%d")

ggplot(calories_data, aes(x= ActivityDay, y=Calories, group=Id, color = Id)) 
  geom_line()  
  scale_x_date(date_breaks = "5 day", date_labels = "%m/%d")

CodePudding user response：

To get the correct date from as.Date, you could incorporate the year first per below. From your plot image, it looks like the dates are input in month/day character format.

library(tidyverse)

calories_data <- tribble(
  ~ActivityDay, ~Calories, ~Id,
  "5/1", 10, 1,
  "5/2", 20, 1,
  "5/10", 15, 2,
  "5/11", 30, 2
)

calories_data |> 
  mutate(ActivityDay = str_c("2022/", ActivityDay),
         ActivityDay = as.Date(ActivityDay)) |> 
  ggplot(aes(ActivityDay, Calories, group = Id, color = Id))  
  geom_line()

^{Created on 2022-06-23 by the reprex package (v2.0.1)}