ggplot x-axis labels with all x-axis values

Question

I'm plotting ggplot with geom_point. The x-axis will be individuals' ID, and y-axis is variable A. How can I ggplot all and individual ID values on the x-axis without overlapping labels? ID may not be continuous.

df sample (actual rows are much longer)

> df
ID     A
1      4
2      12
3      45
5      1

Code for the plot:

ggplot(df, aes(x = ID, y = A)) + geom_point()

Above code has x-axis in intervals, but not presenting individual ID.

Thanks!

Answer 1

Just add + xlim() and + ylim() to show the full x axis and y axis (i.e. to make the x axis and y axis start at zero).

Reproducible example

If this is your ggplot:

iris %>% 
  ggplot(aes(x=Sepal.Length, y=Sepal.Width)) +
  geom_point() 

simply add these two lines to make the x and y axes start at zero:

iris %>% 
  ggplot(aes(x=Sepal.Length, y=Sepal.Width)) +
  geom_point() +     
  xlim(0, 8.2) +     # add this line for x axis limits
  ylim(0, 4.5)       # add this line for y axis limits