connecting points

Question

I have the following plot

require(ggplot2)

dtf <- structure(list(Variance = c(5.213, 1.377, 0.858, 0.613, 0.412, 0.229, 0.139, 0.094, 0.064), Component =         


        

Answer 1

This would plot the points with x as the integer values of the factor categories:

 ggplot(dtf, aes(x = as.numeric(Component), y = Variance)) +
      geom_point() + geom_line()

You can put back in the category labels with:

ggplot(dtf, aes(x = as.numeric(Component), y = Variance)) +
  geom_point() +geom_line() + scale_x_discrete(labels=dtf$Component)

Answer 2

Your x values are discrete (factor) and geom_line() each unique x value perceive as separate group and tries to connect points only inside this group. Setting group=1 in aes() ensures that all values are treated as one group.

ggplot(dtf, aes(x = Component, y = Variance,group=1)) +
  geom_point()+geom_line()