How to Plot Multiple Columns in R (With Examples)

Often you may want to plot multiple columns from a data frame in R. Fortunately this is easy to do using the visualization library ggplot2.

This tutorial shows how to use ggplot2 to plot multiple columns of a data frame on the same graph and on different graphs.

Example 1: Plot Multiple Columns on the Same Graph

The following code shows how to generate a data frame, then “melt” the data frame into a long format, then use ggplot2 to create a line plot for each column in the data frame:

#load necessary libraries
library(ggplot2)
library(reshape2)

#create data frame 
df <- data.frame(index=c(1, 2, 3, 4, 5, 6),
                 var1=c(4, 4, 5, 4, 3, 2),
                 var2=c(1, 2, 4, 4, 6, 9),
                 var3=c(9, 9, 9, 5, 5, 3))

#melt data frame into long format
df <- melt(df ,  id.vars = 'index', variable.name = 'series')

#create line plot for each column in data frame
ggplot(df, aes(index, value)) +
  geom_line(aes(colour = series))

Plot multiple columns in R

Example 2: Plot Multiple Columns on Different Graphs

The following code shows how to generate a data frame, then “melt” the data frame into a long format, then use ggplot2 to create a line plot for each column in the data frame, splitting up each line into its own plot:

#load necessary libraries
library(ggplot2)
library(reshape2)

#create data frame 
df <- data.frame(index=c(1, 2, 3, 4, 5, 6),
                 var1=c(4, 4, 5, 4, 3, 2),
                 var2=c(1, 2, 4, 4, 6, 9),
                 var3=c(9, 9, 9, 5, 5, 3))

#melt data frame into long format
df <- melt(df ,  id.vars = 'index', variable.name = 'series')

#create line plot for each column in data frame
ggplot(df, aes(index, value)) +
  geom_line() +
  facet_grid(series ~ .)

Plot multiple columns in R using ggplot2