ggstatsplot: ggplot2
Based Plots with Statistical Details
Overview
ggstatsplot
is an
extension of ggplot2
package
for creating graphics with details from statistical tests included in
the plots themselves and targeted primarily at behavioral sciences
community to provide a one-line code to produce information-rich plots.
Currently, it supports only the most common types of statistical tests
(parametric, nonparametric, and robust versions of
t-tets/anova, correlation, and contingency tables analyses).
It, therefore, produces a limited kinds of plots for the supported analyses:
- violin plots (for comparisons between groups or conditions),
- pie charts (for categorical data),
- scatterplots (for correlations between two variables),
- correlation matrices (for correlations between multiple variables),
- histograms (for hypothesis about distributions), and
- dot-and-whisker plots (for regression models).
In addition to these basic plots, ggstatsplot
also provides grouped_
versions of all functions that makes it easy to repeat the same anlysis
for any grouping variable.
Future versions will include other types of analyses and plots as well.
Installation
To get the latest, stable CRAN release:
utils::install.packages(pkgs = "ggstatsplot")
You can get the development version from GitHub. If you are in hurry and want to reduce the time of installation, prefer-
# needed package to download from GitHub repo
utils::install.packages(pkgs = "devtools")
# downloading the package from GitHub
devtools::install_github(
repo = "IndrajeetPatil/ggstatsplot", # package path on GitHub
dependencies = FALSE, # assumes that you already have all packages installed needed for this package to work
quick = TRUE # skips docs, demos, and vignettes
)
If time is not a constraint-
devtools::install_github(
repo = "IndrajeetPatil/ggstatsplot", # package path on GitHub
dependencies = TRUE, # installs packages which ggstatsplot depends on
upgrade_dependencies = TRUE # updates any out of date dependencies
)
If you are not using the RStudio IDE and you
get an error related to “pandoc” you will either need to remove the
argument build_vignettes = TRUE
(to avoid building the vignettes) or
install pandoc. If you have the rmarkdown
R
package installed then you can check if you have pandoc by running the
following in R:
rmarkdown::pandoc_available()
#> [1] TRUE
Citation
If you want to cite this package in a scientific journal or in any other context, run the following code in your R console:
utils::citation(package = "ggstatsplot")
Help
There is a dedicated website to ggstatplot
, which is updated after
every new commit: https://indrajeetpatil.github.io/ggstatsplot/.
In R
, documentation for any function can be accessed with the standard
help
command-
?ggbetweenstats
?ggscatterstats
?gghistostats
?ggpiestats
?ggcorrmat
?ggcoefstats
?combine_plots
?grouped_ggbetweenstats
?grouped_ggscatterstats
?grouped_gghistostats
?grouped_ggpiestats
?grouped_ggcorrmat
Usage
ggstatsplot
relies on non-standard
evaluation,
which means you shouldn’t enter arguments in the following manner:
data = NULL, x = data$x, y = data$y
. You must always specify the
data
argument for all functions.
Additionally, ggstatsplot
is a very chatty package and will by default
output information about references for tests, notes on assumptions
about linear models, and warnings. If you don’t want your console to be
cluttered with such messages, they can be turned off by setting argument
messages = FALSE
in the function call.
Here are examples of the main functions currently supported in
ggstatsplot
. Note: The documentation below is for the
development version of the package. So you may see some features
available here that are not currently present in the stable version of
this package on CRAN:
https://cran.r-project.org/web/packages/ggstatsplot/index.html
ggbetweenstats
This function creates either a violin plot, a box plot, or a mix of two for between-group or between-condition comparisons with results from statistical tests in the subtitle. The simplest function call looks like this-
# for reproducibility
set.seed(123)
# plot
ggstatsplot::ggbetweenstats(
data = datasets::iris,
x = Species,
y = Sepal.Length,
messages = FALSE
)
Number of other arguments can be specified to make this plot even more
informative and, additionally, this function returns a ggplot2
object
and thus any of the graphics layers can be further modified:
library(ggplot2)
# for reproducibility
set.seed(123)
# plot
ggstatsplot::ggbetweenstats(
data = datasets::iris,
x = Species,
y = Sepal.Length,
notch = TRUE, # show notched box plot
mean.plotting = TRUE, # whether mean for each group id to be displayed
type = "parametric", # which type of test is to be run
outlier.tagging = TRUE, # whether outliers need to be tagged
outlier.label = Sepal.Width, # variable to be used for the outlier tag
xlab = "Type of Species", # label for the x-axis variable
ylab = "Attribute: Sepal Length", # label for the y-axis variable
title = "Dataset: Iris flower data set", # title text for the plot
caption = expression( # caption text for the plot
paste(italic("Note"), ": this is a demo")
),
ggtheme = ggplot2::theme_grey(), # choosing a different theme
palette = "Set1", # choosing a different color palette
messages = FALSE
) + # further modification outside of ggstatsplot
ggplot2::coord_cartesian(ylim = c(3, 8)) +
ggplot2::scale_y_continuous(breaks = seq(3, 8, by = 1))
The type
(of test) argument also accepts the following abbreviations:
"p"
(for parametric), "np"
(for nonparametric), "r"
(for
robust). Additionally, the type of plot to be displayed can also be
modified ("box"
, "violin"
, or "boxviolin"
).
Variant of this function ggwithinstats
is currently under work. You
can still use this function just to prepare the plot for
exploratory data analysis, but the statistical details displayed in the
subtitle will be incorrect. You can remove them by adding +
ggplot2::labs(subtitle = NULL)
.
For more, see the ggbetweenstats
vignette:
https://indrajeetpatil.github.io/ggstatsplot/articles/ggbetweenstats.html
ggscatterstats
This function creates a scatterplot with marginal histograms/boxplots/density/violin plots from and results from statistical tests in the subtitle:
ggstatsplot::ggscatterstats(
data = datasets::iris,
x = Sepal.Length,
y = Petal.Length,
title = "Dataset: Iris flower data set",
messages = FALSE
)
Number of other arguments can be specified to modify this basic plot-
library(datasets)
# for reproducibility
set.seed(123)
# plot
ggstatsplot::ggscatterstats(
data = subset(datasets::iris, iris$Species == "setosa"),
x = Sepal.Length,
y = Petal.Length,
type = "robust", # type of test that needs to be run
xlab = "Attribute: Sepal Length", # label for x axis
ylab = "Attribute: Petal Length", # label for y axis
line.color = "black", # changing regression line color line
title = "Dataset: Iris flower data set", # title text for the plot
caption = expression( # caption text for the plot
paste(italic("Note"), ": this is a demo")
),
marginal.type = "density", # type of marginal distribution to be displayed
xfill = "blue", # color fill for x-axis marginal distribution
yfill = "red", # color fill for y-axis marginal distribution
centrality.para = "median", # which type of central tendency lines are to be displayed
width.jitter = 0.2, # amount of horizontal jitter for data points
height.jitter = 0.4, # amount of vertical jitter for data points
messages = FALSE # turn off messages and notes
)
For more, see the ggscatterstats
vignette:
https://indrajeetpatil.github.io/ggstatsplot/articles/ggscatterstats.html
ggpiestats
This function creates a pie chart for categorical variables with results from contingency table analysis included in the subtitle of the plot. If only one categorical variable is entered, results from one-sample proportion test will be displayed as a subtitle.
# for reproducibility
set.seed(123)
# plot
ggstatsplot::ggpiestats(
data = datasets::iris,
main = Species,
messages = FALSE
)
This function can also be used to study an interaction between two
categorical variables. Additionally, as with the other functions in
ggstatsplot
, this function returns a ggplot2
object and can further
be modified with ggplot2
syntax (e.g., we can change the color palette
after ggstatsplot
has produced the plot)-
library(ggplot2)
# for reproducibility
set.seed(123)
# plot
ggstatsplot::ggpiestats(
data = datasets::mtcars,
main = cyl,
condition = am,
title = "Dataset: Motor Trend Car Road Tests",
messages = FALSE
) + # further modification outside of ggstatsplot to change the default palette as an example
ggplot2::scale_fill_brewer(palette = "Set1")
As with the other functions, this basic plot can further be modified with additional arguments:
# for reproducibility
set.seed(123)
# plot
ggstatsplot::ggpiestats(
data = datasets::mtcars,
main = am,
condition = cyl,
title = "Dataset: Motor Trend Car Road Tests", # title for the plot
stat.title = "interaction: ", # title for the results from Pearson's chi-squared test
legend.title = "Transmission", # title for the legend
factor.levels = c("1 = manual", "0 = automatic"), # renaming the factor level names for 'main' variable
facet.wrap.name = "No. of cylinders", # name for the facetting variable
facet.proptest = FALSE, # turning of facetted proportion test results
caption = expression( # text for the caption
paste(italic("Note"), ": this is a demo")
),
messages = FALSE # turn off messages and notes
)
For more, including information about the variant of this function
grouped_ggpiestats
, see the ggpiestats
vignette:
https://indrajeetpatil.github.io/ggstatsplot/articles/ggpiestats.html
gghistostats
In case you would like to see the distribution of one variable and check if it is significantly different from a specified value with a one sample test, this function will let you do that.
library(datasets)
ggstatsplot::gghistostats(
data = datasets::iris,
x = Sepal.Length,
title = "Distribution of Iris sepal length",
type = "parametric", # one sample t-test
test.value = 3, # default value is 0
centrality.para = "mean", # which measure of central tendency is to be plotted
centrality.color = "darkred", # decides color of vertical line representing central tendency
binwidth = 0.10, # binwidth value (needs to be toyed around with until you find the best one)
messages = FALSE # turn off the messages
)
The type
(of test) argument also accepts the following abbreviations:
"p"
(for parametric) or "np"
(for nonparametric) or "bf"
(for
Bayes Factor).
ggstatsplot::gghistostats(
data = NULL,
title = "Distribution of variable x",
x = stats::rnorm(n = 1000, mean = 0, sd = 1),
test.value = 1,
test.value.line = TRUE,
test.value.color = "black",
centrality.para = "mean",
type = "bf",
bf.prior = 0.8,
messages = FALSE,
caption = expression(
paste(italic("Note"), ": black line - test value; blue line - observed mean")
)
)
As seen here, by default, Bayes Factor quantifies the support for the alternative hypothesis (H1) over the null hypothesis (H0) (i.e., BF10 is displayed).
For more, including information about the variant of this function
grouped_gghistostats
, see the gghistostats
vignette:
https://indrajeetpatil.github.io/ggstatsplot/articles/gghistostats.html
ggcorrmat
ggcorrmat
makes correlalograms with minimal amount of code. Just
sticking to the defaults itself produces publication-ready correlation
matrices. (Wrapper around
ggcorrplot
)
# as a default this function outputs a correlalogram plot
ggstatsplot::ggcorrmat(
data = datasets::iris,
corr.method = "spearman", # correlation method
sig.level = 0.005, # threshold of significance
cor.vars = Sepal.Length:Petal.Width, # a range of variables can be selected
cor.vars.names = c("Sepal Length", "Sepal Width", "Petal Length", "Petal Width"),
title = "Correlalogram for length measures for Iris species",
subtitle = "Iris dataset by Anderson",
caption = expression(
paste(
italic("Note"),
": X denotes correlation non-significant at ",
italic("p "),
"< 0.005; adjusted alpha"
)
)
)
Multiple arguments can be modified to change the appearance of the correlation matrix.
Alternatively, you can use it just to get the correlation matrices and
their corresponding p-values (in a
tibble format). This is especially
useful for robust correlation coefficient, which is not currently
supported in ggcorrmat
plot.
# getting the correlation coefficient matrix
ggstatsplot::ggcorrmat(
data = datasets::iris,
cor.vars = Sepal.Length:Petal.Width,
corr.method = "robust",
output = "correlations", # specifying the needed output
digits = 3 # number of digits to be dispayed for correlation coefficient
)
#> # A tibble: 4 x 5
#> variable Sepal.Length Sepal.Width Petal.Length Petal.Width
#> <chr> <dbl> <dbl> <dbl> <dbl>
#> 1 Sepal.Length 1 -0.143 0.878 0.837
#> 2 Sepal.Width -0.143 1 -0.426 -0.373
#> 3 Petal.Length 0.878 -0.426 1 0.966
#> 4 Petal.Width 0.837 -0.373 0.966 1
# getting the p-value matrix
ggstatsplot::ggcorrmat(
data = datasets::iris,
cor.vars = Sepal.Length:Petal.Width,
corr.method = "robust",
output = "p-values"
)
#> # A tibble: 4 x 5
#> variable Sepal.Length Sepal.Width Petal.Length Petal.Width
#> <chr> <dbl> <dbl> <dbl> <dbl>
#> 1 Sepal.Length 0 0.0818 0 0
#> 2 Sepal.Width 0.0818 0 0.0000000529 0.00000252
#> 3 Petal.Length 0 0.0000000529 0 0
#> 4 Petal.Width 0 0.00000252 0 0
For examples and more information, see the ggcorrmat
vignette:
https://indrajeetpatil.github.io/ggstatsplot/articles/ggcorrmat.html
ggcoefstats
ggcoefstats
creates a lot with the regression coefficients’ point
estimates as dots with confidence interval whiskers. This is a wrapper
function around GGally::ggcoef
.
ggstatsplot::ggcoefstats(x = stats::lm(formula = mpg ~ am * cyl,
data = mtcars))
The basic can be further modified to one’s liking with additional arguments:
ggstatsplot::ggcoefstats(
x = stats::lm(formula = mpg ~ am * cyl,
data = mtcars),
point.color = "red",
vline.color = "#CC79A7",
vline.linetype = "dotdash",
stats.label.size = 3.5,
stats.label.color = c("#0072B2", "#D55E00", "darkgreen"),
title = "Car performance predicted by transmission and cylinder count",
subtitle = "Source: 1974 Motor Trend US magazine"
) +
# further modification with the ggplot2 commands
# note the order in which the labels are entered
ggplot2::scale_y_discrete(labels = c("transmission", "cylinders", "interaction")) +
ggplot2::labs(x = "regression coefficient",
y = NULL)
All the regression model classes that are supported in the broom
package with tidy
and glance
methods
(https://broom.tidyverse.org/articles/available-methods.html) are also
supported by ggcoefstats
. Let’s see few examples:
library(dplyr)
library(lme4)
# for reproducibility
set.seed(200)
# creating dataframes needed for the analysis below
d <- as.data.frame(Titanic)
# combining plots together
ggstatsplot::combine_plots(
# generalized linear model
ggstatsplot::ggcoefstats(
x = stats::glm(
formula = Survived ~ Sex + Age,
data = d,
weights = d$Freq,
family = "binomial"
),
exponentiate = TRUE,
exclude.intercept = FALSE,
title = "generalized linear model"
),
# nonlinear least squares
ggstatsplot::ggcoefstats(
x = stats::nls(
formula = mpg ~ k / wt + b,
data = mtcars,
start = list(k = 1, b = 0)
),
point.color = "darkgreen",
title = "non-linear least squares"
),
# linear mmodel
ggstatsplot::ggcoefstats(
x = lme4::lmer(
formula = Reaction ~ Days + (Days | Subject),
data = lme4::sleepstudy
),
point.color = "red",
exclude.intercept = TRUE,
title = "linear mixed-effects model"
),
# generalized linear mixed-effects model
ggstatsplot::ggcoefstats(
x = lme4::glmer(
formula = cbind(incidence, size - incidence) ~ period + (1 | herd),
data = lme4::cbpp,
family = binomial
),
exclude.intercept = FALSE,
title = "generalized linear mixed-effects model"
),
labels = c("(a)", "(b)", "(c)", "(d)"),
nrow = 2,
ncol = 2
)
This is by no means an exhaustive list of models supported by
ggcoefstats
. For more, see the associated vignette-
https://indrajeetpatil.github.io/ggstatsplot/articles/ggcoefstats.html
combine_plots
ggstatsplot
also contains a helper function combine_plots
to combine
multiple plots. This is a wrapper around and lets you combine multiple
plots and add combination of title, caption, and annotation texts with
suitable default parameters.
The full power of ggstatsplot
can be leveraged with a functional
programming package like purrr
that
replaces many for loops with code that is both more succinct and easier
to read and, therefore, purrr
should be preferrred.
For more, see the associated vignette- https://indrajeetpatil.github.io/ggstatsplot/articles/combine_plots.html
theme_mprl
All plots from ggstatsplot
have a default theme: theme_mprl
. For
more on how to modify it, see the associated vignette-
https://indrajeetpatil.github.io/ggstatsplot/articles/theme_mprl.html