plotting in R with changing y axis

Question

I have a dataframe which looks like this:

da <- data.frame("a"=c(1,2.5,3,4.5,4),"b"=c(1.5,2.7,3.2,4.7,4.2))

    a   b
1 1.0 1.5
2 2.5 2.7
3 3.0 3.2
4 4.5 4.7
5 4.0 4.2

I want to plot the above values for a and b where labels on the x axis are a and b while ylim ranges from 0 to 10. So basically all the values of a should be plotted parallel to yaxis and then some distance apart, values of b should be plotted parallel to yaxis. I tried using the plot function but cannot get it to work. Any help would be appreciated.

Answer 1

library(tidyr)
library(ggplot2)

ggplot(data = gather(da, category, value), aes(x=category, y=value)) +
  geom_point() +
  ylim(0,10)

Answer 2

You are describing a strip chart:

stripchart(da, vertical=TRUE)