用加号打印正数

Question

我正在计算年份和参考年份之间的差异.我想将结果用作图中的x值.但是如何用正数(-2,-1,0,+ 1,+ 2)打印+号？

dat <- data.frame(year = c(2000, 2001, 2002, 2003, 2004), ref = rep(2002)) 
dat$diff <- dat$year - dat$ref

ggplot(dat, aes(x = diff))

Answer 1

你可以做到

library(ggplot2)
dat <- data.frame(year = c(2000, 2001, 2002, 2003, 2004), ref = rep(2002)) 
dat$diff <- dat$year - dat$ref
ggplot(dat, aes(x = diff)) + 
  scale_x_continuous(labels = function(x) sprintf("%+d", x))