Question

I am trying to create a simple line plot and jitter the lines.

library(ggplot2)
test=read.table(text= "
  group  x  y
  1 1   17  
  1 2   16  
  2 1   13
  2 2   12.5
  ", header=TRUE, sep=""  )        

pd <- position_dodge(.2)

qplot(x=x, y=y, data=test, group=group, colour=group ) +
geom_line(position=pd )+
geom_point(position=pd, size=6)

I am getting

ymax not defined: adjusting position using y instead
ymax not defined: adjusting position using y instead

warnings and somehow two symbols are displayed for each data point instead of one:

I assume the ymax warning has something to do with getting two symbols. I’d appreciate any help. thanks!

Answer 1

library(ggplot2)
test=read.table(text= "
  group  x  y
  1 1   17  
  1 2   16  
  2 1   13
  2 2   12.5
  ", header=TRUE, sep=""  )        

ggplot(data=test, aes(x=x, y=y, group=group, colour=group)) + 
  geom_line(position=position_dodge(0.2))+
  geom_point(position=position_dodge(0.2))