plotting-objects-not-found

[noamross]

https://github.com/noamross/zero-dependency-problems/blob/master/R/plotting-objects-not-found.md

I tried plotting for the first question and got:

subset(ChickWeight, Chick == 1)
weight Time Chick Diet
1 42 0 1 1
2 51 2 1 1
3 59 4 1 1
4 64 6 1 1
5 76 8 1 1
6 93 10 1 1
7 106 12 1 1
8 125 14 1 1
9 149 16 1 1
10 171 18 1 1
11 199 20 1 1
12 205 21 1 1

plot( log_weight, log_Time, main="Scatter plot of weight vs Time", xlab="log Time", ylab="log weight" )

Error in plot(log_weight, log_Time, main = "Scatter plot of weight vs Time", :
object 'log_weight' not found

what am I doing wrong here?