Basic Syntax
library(ggplot2)
ggplot(iris,aes(Sepal.Width,Sepal.Length))+geom_point()
Additional Features
Add Groups/Colors
ggplot(iris,aes(Sepal.Width,Sepal.Length,color=Species))+geom_point()
Increase Size
ggplot(iris,aes(Sepal.Width,Sepal.Length,color=Species))+geom_point(size=4)
Variable Size
ggplot(iris,aes(Sepal.Width,Sepal.Length,color=Species,size=Petal.Length))+geom_point()
Aesthetics
Add Outlines to points
Here the key is to use shape=21 or pch=21. Values from 21-25 in the shape or pch parameter will separately specify the fill and color argument
ggplot(iris,aes(Sepal.Width,
Sepal.Length,
size=Petal.Length,
fill=Species))+ # Change Fill color based on Species
geom_point(shape=21, # Set shape/pch to be circle with outline
color='black', # Set outline to be black
alpha=0.8) # Add some transparency
Changing Themes
Modify Axes
standard_theme <-
theme(axis.text.x=element_text(size=14), # Change x-axis value text-size
axis.title.x=element_text(size=18), # Change x-axis label text-size
axis.text.y=element_text(size=14), # Change y-axis value text-size
axis.title.y=element_text(size=18), # Change y-axis label text-size
legend.text=element_text(size=14), # Change legend value text-size
legend.title=element_text(size=16)) # Change legend title text-size
ggplot(iris,aes(Sepal.Width,
Sepal.Length,
size=Petal.Length,
fill=Species))+ # Change Fill color based on Species
geom_point(shape=21, # Set shape/pch to be circle with outline
color='black', # Set outline to be black
alpha=0.8)+ # Add some transparency
scale_x_continuous('Sepal Width')+ # Add label to x-axis
scale_y_continuous('Sepal Length')+ # Add label to y-axis
scale_fill_discrete('Iris Species')+ # Add label to Legend
scale_size_continuous('Petal Length')+ # Add Label to Legend
standard_theme # Modify axis/legend element size