ggplot2 error: geom_line requires the following missing aesthetics: y - r

Question

I am trying to plot several line graphs from a list using a loop in R. The list temp.list looks like this:
> temp.list[1]
$`1`
NEW_UPC Week1 Week2 Week3 Week4 Week5 Week6 Week7 Week8 Week9 Week10 Week11 Week12
5 11410008398 3 6 11 15 15 27 31 33 34 34 34 34
Life Status Num_markets Sales
5 197 1 50 186048.1
I use only some part of the data above to plot, specifically items 2 to 13 in the list will go on the y-axis, i.e. 3,6,11,15,...,34. For x-axis, I would like to have Week 1, Week 2, ..., Week 12 at the tick marks. As I don't know how to assign character values to x in gglplot command, I created a variable called weeks for x-axis as below:
weeks = c(1,2,3,4,5,6,7,8,9,10,11,12)
The code that I used to generate the plot is below:
for (i in 1:2) {
markets= temp.list[[i]][2:13]
ggplot(data = NULL,aes(x=weeks,y=markets))+geom_line()+
scale_x_continuous(breaks = seq(0,12,1))+
scale_y_continuous(breaks = seq(0,50,5))
}
This code does not generate any plot. When I run just the below lines:
ggplot(data = NULL,aes(x=weeks,y=markets))+geom_line()+
scale_x_continuous(breaks = seq(0,12,1))+
scale_y_continuous(breaks = seq(0,50,5))
I get this error:
Error: geom_line requires the following missing aesthetics: y
In addition: Warning message:
In (function (..., row.names = NULL, check.rows = FALSE, check.names = TRUE, :
row names were found from a short variable and have been discarded
Any help to fix this will be appreciated. I looked at some related discussions here, but I am not clear how to proceed.
Also, any better way to generate multiple plots is also welcome. From temp.list, I am looking to generate over 300 separate line graphs (i.e, not all lines in one chart).

Answer 1

Here is a solution using tidyverse:
library(tidyverse)
# 1: create a function for the plot
## gather will give a long format data.frame
## then extract the number of the week and format it to numeric
## then use ggplot on this data
plot_function <- function(data) {
data %>%
gather(., key = week, value = markets, starts_with("Week")) %>%
mutate(week= as.numeric(str_sub(week, 5, -1))) %>%
ggplot(., aes(x = week, y = markets)) +
geom_line() +
scale_x_continuous(breaks = seq(0, 12, 1)) +
scale_y_continuous(breaks = seq(0, 50, 5))
}
# 2: map the function to your list
plots <- map(temp.list, plot_function)
# 3: access each plot easily
plots[[1]]
plots[[2]]
...
#Data used for this example
temp.list = list('1' = data.frame(NEW_UPC = 11410008398,
Week1 = 3,
Week2 = 6,
Week3 = 11,
Week4 = 15,
Week5 = 15,
Week6 = 27,
Week7 = 31,
Week8 = 33,
Week9 = 34,
Week10 = 34,
Week11 = 34,
Week12 = 34,
Life = 197,
Status = 1,
Num_markets = 50,
Sales = 186048.1),
'2' = data.frame(NEW_UPC = 11410008398,
Week1 = 4,
Week2 = 5,
Week3 = 8,
Week4 = 13,
Week5 = 14,
Week6 = 25,
Week7 = 29,
Week8 = 30,
Week9 = 31,
Week10 = 33,
Week11 = 34,
Week12 = 34,
Life = 201,
Status = 1,
Num_markets = 50,
Sales = 186048.1)
)