Plotting Two Lines

Hi,

I am trying to plot the following data such that both variable y and z vs x.
(ie two lines on a single plot). As the x variable is not numeric, how do I
go about it? Appreciate if any expert could help. 
I know I use plot() follow by lines() to add another line to the plot. But
my problem is i was unable to plot y vs x in the first place.
  

stats787 wrote:

Hi,

I am trying to plot the following data such that both variable y and 
z vs x.
(ie two lines on a single plot). As the x variable is not numeric, 
how do I
go about it? Appreciate if any expert could help. I know I use plot() 
follow by lines() to add another line to the plot. But
my problem is i was unable to plot y vs x in the first place.
  

Hi stats787,
I think this is a replay of a previous problem where the sender 
expected the values on the abcissa to be sorted before plotting. You 
have the additional camoflage of a factor as that set of values. One 
minor problem is that the separator is missing between elements 1 and 
2 in the eighth line. After fixing that, try this (assuming your data 
frame is named "stats787":

plot(as.numeric(stats787$x)[order(stats787$x)],stats787$y,type="l",col="red")                    

lines(as.numeric(stats787$x)[order(stats787$x)],stats787$z,col="green")