install.packages('readxl')
install.packages('ggplot2')

library(readxl)
library(ggplot2)


you<-read_xlsx(‘’\\data.xlsx')#读入文件路径
you$class<-ifelse(you$`y axis`<=25,'a',ifelse(
  you$`y axis`>25&you$`y axis`<=50,'b',ifelse(
    you$`y axis`>50&you$`y axis`<=75,'c','d'
  )
))

p<-ggplot(data=you)+
  geom_point(aes(x=get('x axis'),y=get('y axis'),color=class,shape=class))
p