How to line plot columns from multiple data frame in R?

Question

Thought it would be easy but am running out of ideas here. I have three data.frame that I would like to plot in a single figure such that plot-A would contain line plots using data of column A from all the data.frame i.e., DF1,DF2,DF3, plot-B should contain line plots using data of column B from all data.frame and likewise for C. In the past I use facet_wrap, however, I have no idea how to go about this. here is my simple code which does not produce any plot but will give an idea what I want. A ggplot option would be great.

library(gridExtra)

DF1 = data.frame(Month = 1:12, A = runif(12, 1,10), B = runif(12,5,10), C = runif(12, 3,9))
DF2 = data.frame(Month = 1:12, A = runif(12, 4,13), B = runif(12,6,14), C = runif(12, 3,12))
DF3 = data.frame(Month = 1:12, A = runif(12, 2,15), B = runif(12,1,9), C = runif(12, 3,15))

G1 = plot(DF1$Month, y=DF1$A, "l")
lines(DF2$A, col = "red")
lines(DF3$A, col = "blue")

G2 = plot(DF1$Month, y=DF1$B, "l")
lines(DF2$B, col = "red")
lines(DF3$B, col = "blue")

G3 = plot(DF1$Month, y=DF1$C, "l")
lines(DF2$C, col = "red")
lines(DF3$C, col = "blue")

grid.arrange(G1,G2,G3, ncol = 3)

Note: in my example, I have three columns in each data.frame, however, I would like to apply the code over data.frame that have a large number of columns- not just three. so automating the process would help.

Answer 1

Like this

The only manual step is giving each data.frame an identifying column (possibly automate using this? Add column containing data frame name to a list of data frames)

Then you combine them all into one dataframe and gather the columns so that the data.frame is in long form. You can then use with facet_grid/facet_wrap as you mentioned

DF1 = data.frame(Month = 1:12, A = runif(12, 1,10), B = runif(12,5,10), C = runif(12, 3,9))
DF2 = data.frame(Month = 1:12, A = runif(12, 4,13), B = runif(12,6,14), C = runif(12, 3,12))
DF3 = data.frame(Month = 1:12, A = runif(12, 2,15), B = runif(12,1,9), C = runif(12, 3,15))


DF1$df <- "1"
DF2$df <- "2"
DF3$df <- "3"

library(tidyr)
library(ggplot2)
AllDf <- rbind(DF1,DF2,DF3)

AllDf_l <- AllDf %>% gather(Var,Value, A:C)

ggplot(AllDf_l, aes(x = Month, y = Value, colour = df))+geom_line()+
  facet_grid(Var~.)