# ggbetweenstats

##### Box/Violin plots for group or condition comparisons in between-subjects designs.

A combination of box and violin plots along with jittered data points for between-subjects designs with statistical details included in the plot as a subtitle.

##### Usage

```
ggbetweenstats(data, x, y, plot.type = "boxviolin",
type = "parametric", pairwise.comparisons = FALSE,
pairwise.annotation = "asterisk", pairwise.display = "significant",
p.adjust.method = "holm", effsize.type = "unbiased",
partial = TRUE, effsize.noncentral = TRUE, bf.prior = 0.707,
bf.message = TRUE, results.subtitle = TRUE, xlab = NULL,
ylab = NULL, caption = NULL, title = NULL, subtitle = NULL,
stat.title = NULL, sample.size.label = TRUE, k = 2,
var.equal = FALSE, conf.level = 0.95, nboot = 100, tr = 0.1,
sort = "none", sort.fun = mean, axes.range.restrict = FALSE,
mean.label.size = 3, mean.label.fontface = "bold",
mean.label.color = "black", notch = FALSE, notchwidth = 0.5,
linetype = "solid", outlier.tagging = FALSE, outlier.shape = 19,
outlier.label = NULL, outlier.label.color = "black",
outlier.color = "black", outlier.coef = 1.5, mean.plotting = TRUE,
mean.ci = FALSE, mean.size = 5, mean.color = "darkred",
point.jitter.width = NULL, point.jitter.height = 0,
point.dodge.width = 0.6, ggtheme = ggplot2::theme_bw(),
ggstatsplot.layer = TRUE, package = "RColorBrewer",
palette = "Dark2", direction = 1, ggplot.component = NULL,
return = "plot", messages = TRUE)
```

##### Arguments

- data
A dataframe (or a tibble) from which variables specified are to be taken. A matrix or tables will

**not**be accepted.- x
The grouping variable from the dataframe

`data`

.- y
The response (a.k.a. outcome or dependent) variable from the dataframe

`data`

.- plot.type
Character describing the

*type*of plot. Currently supported plots are`"box"`

(for pure boxplots),`"violin"`

(for pure violin plots), and`"boxviolin"`

(for a combination of box and violin plots; default).- type
Type of statistic expected (

`"parametric"`

or`"nonparametric"`

or`"robust"`

or`"bayes"`

).Corresponding abbreviations are also accepted:`"p"`

(for parametric),`"np"`

(nonparametric),`"r"`

(robust), or`"bf"`

resp.- pairwise.comparisons
Logical that decides whether pairwise comparisons are to be displayed.

**Only significant comparisons**will be shown by default. (default:`FALSE`

). To change this behavior, select appropriate option with`pairwise.display`

argument.- pairwise.annotation
Character that decides the annotations to use for pairwise comparisons. Either

`"p.value"`

or`"asterisk"`

(default).- pairwise.display
Decides which pairwise comparisons to display. Available options are

`"significant"`

(abbreviation accepted:`"s"`

) or`"non-significant"`

(abbreviation accepted:`"ns"`

) or`"everything"`

/`"all"`

. The default is`"significant"`

. You can use this argument to make sure that your plot is not uber-cluttered when you have multiple groups being compared and scores of pairwise comparisons being displayed.- p.adjust.method
Adjustment method for

*p*-values for multiple comparisons. Possible methods are:`"holm"`

(default),`"hochberg"`

,`"hommel"`

,`"bonferroni"`

,`"BH"`

,`"BY"`

,`"fdr"`

,`"none"`

.- effsize.type
Type of effect size needed for

*parametric*tests. The argument can be`"biased"`

(`"d"`

for Cohen's*d*for**t-test**;`"partial_eta"`

for partial eta-squared for**anova**) or`"unbiased"`

(`"g"`

Hedge's*g*for**t-test**;`"partial_omega"`

for partial omega-squared for**anova**)).- partial
Logical that decides if partial eta-squared or omega-squared are returned (Default:

`TRUE`

). If`FALSE`

, eta-squared or omega-squared will be returned. Valid only for objects of class`lm`

,`aov`

,`anova`

, or`aovlist`

.- effsize.noncentral
Logical indicating whether to use non-central

*t*-distributions for computing the confidence interval for Cohen's*d*or Hedge's*g*(Default:`TRUE`

).- bf.prior
A number between

`0.5`

and`2`

(default`0.707`

), the prior width to use in calculating Bayes factors.- bf.message
Logical that decides whether to display Bayes Factor in favor of the

*null*hypothesis. This argument is relevant only**for parametric test**(Default:`TRUE`

).- results.subtitle
Decides whether the results of statistical tests are to be displayed as a subtitle (Default:

`TRUE`

). If set to`FALSE`

, only the plot will be returned.- xlab, ylab
Labels for

`x`

and`y`

axis variables. If`NULL`

(default), variable names for`x`

and`y`

will be used.- caption
The text for the plot caption.

- title
The text for the plot title.

- subtitle
The text for the plot subtitle. Will work only if

`results.subtitle = FALSE`

.- stat.title
A character describing the test being run, which will be added as a prefix in the subtitle. The default is

`NULL`

. An example of a`stat.title`

argument will be something like`"Student's t-test: "`

.- sample.size.label
Logical that decides whether sample size information should be displayed for each level of the grouping variable

`x`

(Default:`TRUE`

).- k
Number of digits after decimal point (should be an integer) (Default:

`k = 2`

).- var.equal
a logical variable indicating whether to treat the variances in the samples as equal. If

`TRUE`

, then a simple F test for the equality of means in a one-way analysis of variance is performed. If`FALSE`

, an approximate method of Welch (1951) is used, which generalizes the commonly known 2-sample Welch test to the case of arbitrarily many samples.- conf.level
Scalar between 0 and 1. If unspecified, the defaults return

`95%`

lower and upper confidence intervals (`0.95`

).- nboot
Number of bootstrap samples for computing confidence interval for the effect size (Default:

`100`

).- tr
Trim level for the mean when carrying out

`robust`

tests. If you get error stating "Standard error cannot be computed because of Winsorized variance of 0 (e.g., due to ties). Try to decrease the trimming level.", try to play around with the value of`tr`

, which is by default set to`0.1`

. Lowering the value might help.- sort
If

`"ascending"`

(default),`x`

-axis variable factor levels will be sorted based on increasing values of`y`

-axis variable. If`"descending"`

, the opposite. If`"none"`

, no sorting will happen.- sort.fun
The function used to sort (default:

`mean`

).- axes.range.restrict
Logical that decides whether to restrict the axes values ranges to

`min`

and`max`

values of the axes variables (Default:`FALSE`

), only relevant for functions where axes variables are of numeric type.- mean.label.size, mean.label.fontface, mean.label.color
Aesthetics for the label displaying mean. Defaults:

`3`

,`"bold"`

,`"black"`

, respectively.- notch
A logical. If

`FALSE`

(default), a standard box plot will be displayed. If`TRUE`

, a notched box plot will be used. Notches are used to compare groups; if the notches of two boxes do not overlap, this suggests that the medians are significantly different. In a notched box plot, the notches extend`1.58 * IQR / sqrt(n)`

. This gives a roughly`95%`

confidence interval for comparing medians. IQR: Inter-Quartile Range.- notchwidth
For a notched box plot, width of the notch relative to the body (default

`0.5`

).- linetype
Character strings (

`"blank"`

,`"solid"`

,`"dashed"`

,`"dotted"`

,`"dotdash"`

,`"longdash"`

, and`"twodash"`

) specifying the type of line to draw box plots (Default:`"solid"`

). Alternatively, the numbers`0`

to`6`

can be used (`0`

for "blank",`1`

for "solid", etc.).- outlier.tagging
Decides whether outliers should be tagged (Default:

`FALSE`

).- outlier.shape
Hiding the outliers can be achieved by setting outlier.shape = NA. Importantly, this does not remove the outliers, it only hides them, so the range calculated for the y-axis will be the same with outliers shown and outliers hidden.

- outlier.label
Label to put on the outliers that have been tagged.

- outlier.label.color
Color for the label to to put on the outliers that have been tagged (Default:

`"black"`

).- outlier.color
Default aesthetics for outliers (Default:

`"black"`

).- outlier.coef
Coefficient for outlier detection using Tukey's method. With Tukey's method, outliers are below (1st Quartile) or above (3rd Quartile)

`outlier.coef`

times the Inter-Quartile Range (IQR) (Default:`1.5`

).- mean.plotting
Logical that decides whether mean is to be highlighted and its value to be displayed (Default:

`TRUE`

).- mean.ci
Logical that decides whether 95 is to be displayed (Default:

`FALSE`

).- mean.size
Point size for the data point corresponding to mean (Default:

`5`

).- mean.color
Color for the data point corresponding to mean (Default:

`"darkred"`

).- point.jitter.width
Numeric specifying the degree of jitter in

`x`

direction. Defaults to`40%`

of the resolution of the data.- point.jitter.height
Numeric specifying the degree of jitter in

`y`

direction. Defaults to`0.1`

.- point.dodge.width
Numeric specifying the amount to dodge in the

`x`

direction. Defaults to`0.60`

.- ggtheme
A function,

`ggplot2`

theme name. Default value is`ggplot2::theme_bw()`

. Any of the`ggplot2`

themes, or themes from extension packages are allowed (e.g.,`ggthemes::theme_fivethirtyeight()`

,`hrbrthemes::theme_ipsum_ps()`

, etc.).- ggstatsplot.layer
Logical that decides whether

`theme_ggstatsplot`

theme elements are to be displayed along with the selected`ggtheme`

(Default:`TRUE`

).- package
Name of package from which the palette is desired as string or symbol.

- palette
If a character string (e.g.,

`"Set1"`

), will use that named palette. If a number, will index into the list of palettes of appropriate type. Default palette is`"Dark2"`

.- direction
Either

`1`

or`-1`

. If`-1`

the palette will be reversed.- ggplot.component
A

`ggplot`

component to be added to the plot prepared by`ggstatsplot`

. This argument is primarily helpful for`grouped_`

variant of the current function. Default is`NULL`

. The argument should be entered as a function. If the given function has an argument`axes.range.restrict`

and if it has been set to`TRUE`

, the added ggplot component*might*not work as expected.- return
Character that describes what is to be returned: can be

`"plot"`

(default) or`"subtitle"`

or`"caption"`

. Setting this to`"subtitle"`

will return the expression containing statistical results, which will be a`NULL`

if you set`results.subtitle = FALSE`

. Setting this to`"caption"`

will return the expression containing details about Bayes Factor analysis, but valid only when`type = "p"`

and`bf.message = TRUE`

, otherwise this will return a`NULL`

.- messages
Decides whether messages references, notes, and warnings are to be displayed (Default:

`TRUE`

).

##### Details

For parametric tests, Welch's ANOVA/*t*-test are used as a default (i.e.,
`var.equal = FALSE`

).
References:

ANOVA: Delacre, Leys, Mora, & Lakens,

*PsyArXiv*, 2018*t*-test: Delacre, Lakens, & Leys,*International Review of Social Psychology*, 2017

If robust tests are selected, following tests are used is .

ANOVA: one-way ANOVA on trimmed means (see

`?WRS2::t1way`

)*t*-test: Yuen's test for trimmed means (see`?WRS2::yuen`

)

For more about how the effect size measures (for nonparametric tests) and
their confidence intervals are computed, see `?rcompanion::wilcoxonR`

.

For repeated measures designs, use `ggwithinstats`

.

##### References

https://indrajeetpatil.github.io/ggstatsplot/articles/web_only/ggbetweenstats.html

##### See Also

`grouped_ggbetweenstats`

, `ggwithinstats`

,
`grouped_ggwithinstats`

, `pairwise_p`

##### Examples

```
# NOT RUN {
# to get reproducible results from bootstrapping
set.seed(123)
library(ggstatsplot)
# simple function call with the defaults
ggstatsplot::ggbetweenstats(
data = mtcars,
x = am,
y = mpg,
title = "Fuel efficiency by type of car transmission",
caption = "Transmission (0 = automatic, 1 = manual)"
)
# }
# NOT RUN {
# more detailed function call
ggstatsplot::ggbetweenstats(
data = datasets::morley,
x = Expt,
y = Speed,
plot.type = "box",
conf.level = 0.99,
xlab = "The experiment number",
ylab = "Speed-of-light measurement",
pairwise.comparisons = TRUE,
pairwise.annotation = "p.value",
p.adjust.method = "fdr",
outlier.tagging = TRUE,
outlier.label = Run,
nboot = 10,
ggtheme = ggplot2::theme_grey(),
ggstatsplot.layer = FALSE
)
# }
```

*Documentation reproduced from package ggstatsplot, version 0.0.11, License: GPL-3 | file LICENSE*