如何更改ggplot中的轴标签？

Question

I created a histogram in R. At the moment, the numbers 1 - 8 are written on the x-axis (for each number a bar). I would like to change the numbers into the wind direction, eg instead of 1, there should stand "west". I tried:

scale_x_discrete(labels=c("1" = "North", "2" = "North East", "3" = "East", "4"= "South East", "5"= "South", "6"="South West", "7"="West", "8"="North West"))

But is not working.I also tried:

scale_x_discrete(breaks=c("1","2","3", "4", "5", "6", "7", "8"), labels=c("North", "North East", "East", "South East", "South", "South West", "West", "North West"))

Here is my script:

options(stringsAsFactors = FALSE)

input1 <- "C:\\Users\\wind_direction.csv"

wind_direction <- read.csv(input1, sep=";")
library(ggplot2)

p3 <- ggplot(wind_direction, aes(x=winddirection)) + 
  geom_bar(color="black", fill="grey", width=0.9)+ 
  theme_bw() +
  scale_y_continuous(limits = c(0, 55), breaks = seq(0,55,10),expand=c(0,0)) +
  scale_x_discrete(labels = c("1" = "North", "2" = "North East", "3" = "East", "4"= "South East", "5"= "South", "6"="South West", "7"="West", "8"="North West"))

print(p3)

Here is a sample of my data:

head(wind_direction)
         day     time winddirection
1 31.07.2018 12:51:57             3
2 31.07.2018 12:55:16             3
3 31.07.2018 12:56:29             3
4 31.07.2018 13:25:05             3
5 31.07.2018 13:36:54             3
6 31.07.2018 13:55:37             3

Answer 1

I think you did a good job with your code and a fast solution involves just to replace aes(x=winddirection) with aes(x=as.character(winddirection)) or aes(x=as.factor(winddirection)) .

So, you just need to be sure that winddirection is character or factor when you map it into x .

Just be sure you have the right labeling. You mention in your question that 1 should be west, but in scale_x_discrete you declare that 1 is north.