R 如何设置 x 和 y 轴值？

Question

I am using this R script for plotting these trend:

archiveorg <- c(9,10,9,10,11,11,10,12,11,10,14,13,17,17,16,13,17,16,18,15,16,16,17,18)
waybacksafn <- c(2,2,4,2,2,2,2,2,1,2,3,2,4,3,3,4,3,3,4,4,1,2,5,7)
waybacknil <- c(5,0,0,0,0,3,3,1,2,3,2,2,2,2,2,2,2,2,2,2,2,2,2,2)

months <-c(1:24)
df <- data.frame(months,archiveorg,waybacksafn,waybacknil)
plot(df$archiveorg,type='n',xlim=c(1,24),ylim=c(1,19),xlab='tempo', ylab='#siti safe csp')
lines(df$archiveorg, type="l", col="red")
lines(df$waybacksafn, type="l", col="blue")
lines(df$waybacknil, type="l", col="black")

axis(1, at=1:24, lab=df$months)
axis(2, las=1, at=seq(1, 19))
legend(1, 19, legend=c("archiveorg", "waybacksafn","waybacknil"),
col=c("red", "blue","black"), lty=1, cex=0.8)

And the result is the following:

On x axes I have values from 1 to 24 (these represents the months from 2018 to the end of 2019). Now i'd like to have only 2018 and 2019 on my x axes (2018 at position 0, and 2019 at position 11).

On y axes I need something similar.. values goes from 1 to 19 but I need only to have 1, 10 and 19 on my axes and no all values.

How can I change my script for this?

Answer 1

You need to draw the plot without axes and specify where you want the breaks and what you want their labels to be:

plot(df$archiveorg,type = 'n', xlim = c(0, 24), ylim = c(0, 19),
     xlab='tempo', ylab='#siti safe csp', yaxt = 'n', xaxt = 'n')
lines(df$archiveorg, type = "l", col = "red")
lines(df$waybacksafn, type = "l", col = "blue")
lines(df$waybacknil, type = "l", col = "black")

axis(1, at = c(0, 11), lab = c(2018, 2019))
axis(2, las = 1, at = c(1, 10, 19))
legend(1, 19, legend = c("archiveorg", "waybacksafn","waybacknil"),
       col=c("red", "blue","black"), lty = 1, cex = 0.8)

Needless to say, it would be easier, prettier and allow more scope for customization to do this in ggplot :

library(tidyverse)
library(lubridate)

df %>% 
  pivot_longer(-1) %>%
  mutate(month = round_date(as.Date("2017-12-01") + 30 * months, "month")) %>%
  ggplot(aes(month, value, colour = name)) + 
  geom_line(size = 1) +
  scale_colour_manual(values = c("red3", "blue4", "cyan3"), name = NULL) +
  scale_x_date(date_breaks = "years", date_labels = "%Y") +
  theme_bw() +
  theme(legend.position = c(0.2, 0.8),
        legend.background = element_rect(color = "black"))