1 Multiple Plots with the Same Axis in R
2 Multiple Plots Side-by-side by Rows in R
3 Multiple Plots Side-by-side by Columns in R
4 Multiple Plots Side-by-side with Margins Adjusted in R

Here we show how to have multiple plots or charts on one graph in R, including with the same axes and side-by-side.

These will be done using the lines(), points(), and par() functions from the "graphics" package.

Some Functions for Multiple Plots on the Same Graph in R
Function	Usage
lines()	Add lines to a plot
points()	Add points to a plot
par(mfrow = c(a, b))	Add plots to graph by row; a rows and b columns
par(mfcol = c(a, b))	Add plots to graph by column; a rows and b columns
par(mar = c(x, y, a, b))	Adjust margins sizes; c(bottom, left, top, right)

1 Multiple Plots with the Same Axis in R

1.1 Example: Scatter Plots

Here we show how to have multiple scatter plots on one plot with the same axis. We make the first scatter plot, then add points from the second and third scatter plots sequentially using the point() function. You can add as many colored points as needed.

set.seed(123)
v1 = rnorm(20)
v2 = rnorm(20) + rnorm(20)/3
v3 = rnorm(20) + rnorm(20)/4
v3 = rnorm(20) + rnorm(20)/5
v4 = rnorm(20) + rnorm(20)/6

# First points from the first scatter plot
plot(v2, v1,
     xlim = range(c(v1, v2, v3, v4)),
     ylim = range(c(v1, v2, v3, v4)),
     col = "turquoise",
     main = "Multiple Scatter Plots on the Same Graph")

# Add more points
points(v3, v1, col = "red", cex = 1.5, pch = 3)
points(v4, v1, col = "black", cex = 1.2, pch = 4)

Multiple Plots with the Same Axis in R: Scatter Plots

1.2 Example: Density Plots

Here we show how to have multiple density plots on one plot with the same axis. We make the first density plot, then add lines from the second and third plots using the lines() function. You can add as many lines as needed.

set.seed(123)
v1 = rnorm(50, 5, 1)
d1 = density(v1)
v2 = rnorm(50, 6, 1)
d2 = density(v2)
v3 = rnorm(50, 5.5, 1)
d3 = density(v3)

# First line from the first density plot
plot(d1,
     xlim = range(c(d1$x, d2$x, d3$x)),
     ylim = range(c(d1$y, d2$y, d3$y)),
     col = "blue",
     main = "Multiple Density Plots on the Same Graph")

# Add the second and third lines
lines(d2, col = "red", lty = 3, lwd = 3)
lines(d3, col = "green", lty = 4, lwd = 2.5)

Multiple Plots with Same Axis in R: Density Plots

1.3 Example: Line Charts

Here we show how to have multiple line charts on one plot with the same axis. We make the first line chart, then add a line from the second chart using the lines() function. You can add as many line charts as needed.

1.4 Example: Histograms

Here we show how to have multiple histograms on one plot with the same axis. We have the histograms stacked sharing the same x-axis at the bottom. This histogram plot type example is applicable to other plot types as well.

set.seed(12)
v1 = rnorm(100, 10, 2)
v2 = rnorm(100, 11, 2)
v3 = rnorm(100, 9, 2)

# Set the limits of the x-axis
lower = floor(min(c(v1, v2, v3)))
upper = ceiling(max(c(v1, v2, v3)))

# Set 3 rows and 1 column of histograms
par(mfrow = c(3, 1))

# Make the plots
hist(v1, xaxt = "n", main = "Histogram 1",
     xlim = c(lower, upper))
hist(v2, xaxt = "n", main = "Histogram 2",
     xlim = c(lower, upper))
hist(v3, main = "Histogram 3",
     xlim = c(lower, upper))

Multiple Plots with the Same Axis in R: Histograms

2 Multiple Plots Side-by-side by Rows in R

Here we show how to have multiple plots side-by-side by rows. Use the par(mfrow = c(a, b)) function to add plots side-by-side by a rows.

# Set 2 rows and 3 columns of plots
par(mfrow = c(2, 3))

# Add the plots
hist(rnorm(200, 5, 1), main = "Plot 1")
plot(rexp(200), type = "l", main = "Plot 2")
boxplot(rnorm(200) ~ rep(c("Grp1", "Grp2"), each = 100), main = "Plot 3")
plot(rnorm(100), rnorm(100), main = "Plot 4")
plot(density(rexp(200)), main = "Plot 5")

Multiple Plots Side-by-side by Rows in R

3 Multiple Plots Side-by-side by Columns in R

Here we show how to have multiple plots side-by-side by columns. Use the par(mfcol = c(a, b)) function to add plots side-by-side by b columns.

# Set 3 rows and 2 columns of plots
par(mfcol = c(3, 2))

# Add the plots
hist(rnorm(200, 5, 1), main = "Plot 1")
plot(rexp(200), type = "l", main = "Plot 2")
boxplot(rnorm(200) ~ rep(c("Grp1", "Grp2"), each = 100), main = "Plot 3")
plot(rnorm(100), rnorm(100), main = "Plot 4")
plot(density(rexp(200)), main = "Plot 5")

Multiple Plots Side-by-side by Columns in R

4 Multiple Plots Side-by-side with Margins Adjusted in R

Here we show how to adjust the margins of multiple plots and bring them closer to each. Use the par(mar = c(bottom, left, top, right)) function to adjust the margins. The default is c(bottom, left, top, right) = c(5, 4, 4, 2). Here we use c(2, 4, 4, 2), changing the bottom from 5 to 2. This removes the x-axis labels and brings the plots closer together.

# Set 2 rows and 3 columns of plots
par(mfrow = c(2, 3))

# Adjust margins to bring the plots closer
par(mar = c(2, 4, 4, 2))

# Add the plots
plot(rnorm(100), rnorm(100), main = "Plot 1")
plot(density(rexp(200)), main = "Plot 2")
hist(rnorm(200, 5, 1), main = "Plot 3")
boxplot(rnorm(200) ~ rep(c("Grp1", "Grp2"), each = 100), main = "Plot 4")
plot(rexp(200), type = "l", main = "Plot 5")

Multiple Plots Side-by-side with Margins Adjusted in R

Multiple Plots on the Same Graph in R