Show all date values on ggplot x axis - R

Question

In the following little dataset, I would like to plot date values on the x axis. I want all ticks of the dates present in the dataframe to be labelled. At the moment it is o

Answer 1

You can supply melt$Sample as the breaks. You'll probably also want to rotate the axis labels to avoid overlap.

ggplot(melt, aes(x = Sample, y = value, colour = variable, group = variable)) +
  facet_wrap(~Treatment) +
  geom_point() +
  geom_line() + 
  scale_x_date(breaks = melt$Sample) + 
  theme(axis.text.x = element_text(angle = 90))