pacman::p_load(ggrepel, patchwork,
ggthemes, hrbrthemes,
tidyverse) Hands-on Exercise 2: Creating Elegant Graphics with ggplot2
1. Getting Started
Install and launching R packages
The code chunck below will be used to check if these packages have been installed and also will load them onto your working R environment.
Importing the data
exam_data <- read_csv("data/Exam_data.csv")Rows: 322 Columns: 7
── Column specification ────────────────────────────────────────────────────────
Delimiter: ","
chr (4): ID, CLASS, GENDER, RACE
dbl (3): ENGLISH, MATHS, SCIENCE
ℹ Use `spec()` to retrieve the full column specification for this data.
ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.2. Exercises
2.1 Working with ggrepel
ggrepel helps to repel overlapping text
ggplot(data=exam_data,
aes(x= MATHS,
y=ENGLISH)) +
geom_point() +
geom_smooth(method=lm,
size=0.5) +
geom_label(aes(label = ID),
hjust = .5,
vjust = -.5) +
coord_cartesian(xlim=c(0,100),
ylim=c(0,100)) +
ggtitle("English scores versus Maths scores for Primary 3")Warning: Using `size` aesthetic for lines was deprecated in ggplot2 3.4.0.
ℹ Please use `linewidth` instead.`geom_smooth()` using formula = 'y ~ x'
Simply replace geom_text() by geom_text_repel() and geom_label() by geom_label_repel.
ggplot(data=exam_data,
aes(x= MATHS,
y=ENGLISH)) +
geom_point() +
geom_smooth(method=lm,
size=0.5) +
geom_label_repel(aes(label = ID),
fontface = "bold") +
coord_cartesian(xlim=c(0,100),
ylim=c(0,100)) +
ggtitle("English scores versus Maths scores for Primary 3")`geom_smooth()` using formula = 'y ~ x'Warning: ggrepel: 317 unlabeled data points (too many overlaps). Consider
increasing max.overlaps
2.2 Working with Themes
8 Built-in Themes: theme_gray(), theme_bw(), theme_classic(), theme_dark(), theme_light(), theme_linedraw(), theme_minimal(), and theme_void()
ggplot(data=exam_data,
aes(x = MATHS)) +
geom_histogram(bins=20,
boundary = 100,
color="grey25",
fill="grey90") +
theme_gray() +
ggtitle("Distribution of Maths scores")
Using ggtheme package
In the example below, The Economist theme is used.
ggplot(data=exam_data,
aes(x = MATHS)) +
geom_histogram(bins=20,
boundary = 100,
color="grey25",
fill="grey90") +
ggtitle("Distribution of Maths scores") +
theme_economist()
Using hrbthems package
Provides a base theme that focuses on typographic elements, including where various labels are placed and fonts used.
ggplot(data=exam_data,
aes(x = MATHS)) +
geom_histogram(bins=20,
boundary = 100,
color="grey25",
fill="grey90") +
theme_ipsum(axis_title_size = 18, #increase font size of axis title to 18
base_size = 15, #increase default axis label to 15
grid = "Y") + # keep only y-axis grid lines
ggtitle("Distribution of Maths scores")Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
found in Windows font database
Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
found in Windows font databaseWarning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
family not found in Windows font database
Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
family not found in Windows font database
Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
family not found in Windows font database
Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
family not found in Windows font database
Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
family not found in Windows font database
Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
family not found in Windows font database
Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
family not found in Windows font database
Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
family not found in Windows font database
Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
family not found in Windows font databaseWarning in grid.Call.graphics(C_text, as.graphicsAnnot(x$label), x$x, x$y, :
font family not found in Windows font databaseWarning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
family not found in Windows font database
2.3 Beyond Single Graph
Create composite plot by combining multiple graphs First, create the three statistical graphics below
p1 <- ggplot(data=exam_data,
aes(x = MATHS)) +
geom_histogram(bins=20,
boundary = 100,
color="grey25",
fill="grey90") +
coord_cartesian(xlim=c(0,100)) +
ggtitle("Distribution of Maths scores")
p2 <- ggplot(data=exam_data,
aes(x = ENGLISH)) +
geom_histogram(bins=20,
boundary = 100,
color="grey25",
fill="grey90") +
coord_cartesian(xlim=c(0,100)) +
ggtitle("Distribution of English scores")
p3 <- ggplot(data=exam_data,
aes(x= MATHS,
y=ENGLISH)) +
geom_point() +
geom_smooth(method=lm,
size=0.5) +
coord_cartesian(xlim=c(0,100),
ylim=c(0,100)) +
ggtitle("English scores versus Maths scores for Primary 3")Working with patchwork
Creating patchwork Use ‘+’ to create two columns layout Use ‘/’ to create two row layout (stack) Use ‘()’ to create subplot group Use ‘|’ to place the plots beside each other
((p1 / p2) | p3) +
plot_annotation(tag_levels = 'I') #creating a composite figure with tag`geom_smooth()` using formula = 'y ~ x'
Combining patchwork and themes
((p1 / p2) | p3) & theme_economist()`geom_smooth()` using formula = 'y ~ x'
Insert another plot in a plot with inset_element()
p3 + inset_element(p2,
left = 0.02,
bottom = 0.7,
right = 0.5,
top = 1)`geom_smooth()` using formula = 'y ~ x'