How To Make Scatterplot with Marginal Histograms in R?
In this article, we will discuss how to make a Scatterplot with Marginal Histograms in the R Language.
To do so we will use the ggExtra package of the R Language. The ggExtra is a collection of functions and layers to enhance ggplot2. The ggMarginal() function can be used to add marginal histograms/boxplots/density plots to ggplot2 scatterplots.
Installation:
To install the ggExtra package we use:
install.packages("ggExtra")After installation, we can load the package and use the following function to make a marginal histogram with a scatter plot.
Syntax: ggMarginal( plot, type=”histogram” )
Creating basic scatter plot with marginal histogram:
Here, is a basic scatter plot with marginal histogram using the ggMarginal function of ggExtra package.
R
# load library tidyverse and ggExtralibrary(tidyverse)library(ggExtra) # set themetheme_set(theme_bw(12)) # create x and y vectorxAxis <- rnorm(1000) yAxis <- rnorm(1000) + xAxis + 10 # create sample data framesample_data <- data.frame(xAxis, yAxis) # create scatter plot using ggplot() functionplot <- ggplot(sample_data, aes(x=xAxis, y=yAxis))+ geom_point()+ theme(legend.position="none") # use ggMarginal function to create marginal histogramggMarginal(plot, type="histogram") |
Output:
Output
Color scatter plot with marginal histogram by group:
To color scatter plot by the group we use the col parameter of ggplot() function. To color the marginal histogram by the group we use groupColour and groupfill as true.
Syntax: ggMarginal( plot, type=”histogram”, groupColour = TRUE, groupFill = TRUE )
Example: Here, we have a scatter plot with marginal histograms both colored by the group. We use boolean values for groupColor and groupFill according to formatting preference.
R
# load library tidyverse and ggExtralibrary(tidyverse)library(ggExtra) # set themetheme_set(theme_bw(12)) # create x and y vectorxAxis <- rnorm(1000) yAxis <- rnorm(1000) + xAxis + 10 # create groups in variable using conditional statementsgroup <- rep(1, 1000) group[xAxis > -1.5] <- 2group[xAxis > -0.5] <- 3group[xAxis > 0.5] <- 4group[xAxis > 1.5] <- 5 # create sample data framesample_data <- data.frame(xAxis, yAxis, group) # create scatter plot using ggplot() # function colored by groupplot <- ggplot(sample_data, aes(x=xAxis, y=yAxis, col = as.factor(group)))+ geom_point()+ theme(legend.position="none") # use ggMarginal function to create marginal histogramggMarginal(plot, type="histogram", groupColour = TRUE, groupFill = TRUE ) |
Output:
Output
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