如何仅使用字符值的一部分作为 x 轴

Question

If I am not allowed to add an additional column, how can I select only the year data(the first column of the shown data in picture 1) to appear on the x-axis (see the desired result in picture 2)

Picture 1:the dataset

Picture 2:the desired result

Your help is much appreciated!!!

Answer 1

I would suggest an approach using ggplot2 . In order to obtain what you want, you can use substring() function to extract the first four elements defining start and end position over your quarter variable. You can also use factor() to keep all years instead of showing numeric quantities as ggplot2 uses to do. Here I have added a small example:

library(ggplot2)
#Data
df <- data.frame(quarter=paste0(rep(c(1975:1980),each=4),'-','Q',rep(1:4,6)),
                 v2=seq(0,100,length.out = 24),stringsAsFactors = F)
#Plot
ggplot(df,aes(x=factor(substring(quarter,1,4)),y=v2,group=1))+
  geom_line()+
  xlab('year')+
  theme_bw()+
  theme(axis.text.x = element_text(angle=90))

Output: