Question

Say I have 2 datasets, 1 with 50 days on the x axis and one with 20 days, created with the code

par(mfrow=c(2,1))
data1=rnorm(50)
plot(data1,type='l',xlab='Days')
data2=rnorm(20)
plot(data2,type='l',xlim=c(0,50),xlab='Days')

In reality, day 1 in dataset 2 corresponds to day 20 in dataset 1 so I would like to plot dataset 2 such that the x axis, as above, goes from 0 to 50 but with the data being plotted from x=20 to x = 40. I’m guessing there’s an easy answer but I can’t find it online…

Thank you.

Answer 1

Pass xand y arguments to plot.

plot(20:39,data2,type='l',xlim=c(0,50),xlab='Days')

Though if you are plotting multiple datasets with the same axes, you are better off using ggplot2 or lattice. Your plots will look much better.

all_data <- data.frame(
  day = c(1:50, 20:39),
  y   = c(runif(50), rnorm(20)),
  grp = factor(rep(1:2, times = c(50, 20)))  
)

#ggplot2 style
library(ggplot2)
ggplot(all_data, aes(day, y)) +
  geom_line() +
  facet_grid(grp ~ .)

#lattice style
library(lattice)
xyplot(y ~ day | grp, all_data, type = "l", layout = c(1, 2))