Histogram for distribution of a numeric variable
Histogram with statistical details from one-sample test included in the plot as a subtitle.
gghistostats( data, x, binwidth = NULL, xlab = NULL, title = NULL, subtitle = NULL, caption = NULL, type = "parametric", test.value = 0, bf.prior = 0.707, bf.message = TRUE, effsize.type = "g", conf.level = 0.95, tr = 0.2, digits = 2L, ggtheme = ggstatsplot::theme_ggstatsplot(), results.subtitle = TRUE, bin.args = list(color = "black", fill = "grey50", alpha = 0.7), centrality.plotting = TRUE, centrality.type = type, centrality.line.args = list(color = "blue", linewidth = 1, linetype = "dashed"), ggplot.component = NULL, ... )
data: A data frame (or a tibble) from which variables specified are to be taken. Other data types (e.g., matrix,table, array, etc.) will not
be accepted. Additionally, grouped data frames from {dplyr} should be ungrouped before they are entered as data.
x: A numeric variable from the data frame data.
binwidth: The width of the histogram bins. Can be specified as a numeric value, or a function that calculates width from x. The default is to use the max(x) - min(x) / sqrt(N). You should always check this value and explore multiple widths to find the best to illustrate the stories in your data.
xlab: Label for x axis variable. If NULL (default), variable name for x will be used.
title: The text for the plot title.
subtitle: The text for the plot subtitle. Will work only if results.subtitle = FALSE.
caption: The text for the plot caption. This argument is relevant only if bf.message = FALSE.
type: A character specifying the type of statistical approach:
"parametric""nonparametric""robust""bayes"You can specify just the initial letter.
test.value: A number indicating the true value of the mean (Default: 0).
bf.prior: A number between 0.5 and 2 (default 0.707), the prior width to use in calculating Bayes factors and posterior estimates. In addition to numeric arguments, several named values are also recognized: "medium", "wide", and "ultrawide", corresponding to r scale values of 1/2, sqrt(2)/2, and 1, respectively. In case of an ANOVA, this value corresponds to scale for fixed effects.
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).
effsize.type: Type of effect size needed for parametric tests. The argument can be "d" (for Cohen's d) or "g" (for Hedge's g).
conf.level: Scalar between 0 and 1 (default: 95%
confidence/credible intervals, 0.95). If NULL, no confidence intervals will be computed.
tr: Trim level for the mean when carrying out robust tests. In case of an error, try reducing the value of tr, which is by default set to 0.2. Lowering the value might help.
digits: Number of digits for rounding or significant figures. May also be "signif" to return significant figures or "scientific"
to return scientific notation. Control the number of digits by adding the value as suffix, e.g. digits = "scientific4" to have scientific notation with 4 decimal places, or digits = "signif5" for 5 significant figures (see also signif()).
ggtheme: A {ggplot2} theme. Default value is theme_ggstatsplot(). Any of the {ggplot2} themes (e.g., ggplot2::theme_bw()), or themes from extension packages are allowed (e.g., ggthemes::theme_fivethirtyeight(), hrbrthemes::theme_ipsum_ps(), etc.). But note that sometimes these themes will remove some of the details that {ggstatsplot} plots typically contains. For example, if relevant, ggbetweenstats() shows details about multiple comparison test as a label on the secondary Y-axis. Some themes (e.g. ggthemes::theme_fivethirtyeight()) will remove the secondary Y-axis and thus the details as well.
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.
bin.args: A list of additional aesthetic arguments to be passed to the stat_bin used to display the bins. Do not specify binwidth argument in this list since it has already been specified using the dedicated argument.
centrality.plotting: Logical that decides whether centrality tendency measure is to be displayed as a point with a label (Default: TRUE). Function decides which central tendency measure to show depending on the type argument.
If you want default centrality parameter, you can specify this using centrality.type argument.
centrality.type: Decides which centrality parameter is to be displayed. The default is to choose the same as type argument. You can specify this to be:
"parameteric" (for mean )"nonparametric" (for median )robust (for trimmed mean )bayes (for MAP estimator )Just as type argument, abbreviations are also accepted.
centrality.line.args: A list of additional aesthetic arguments to be passed to the ggplot2::geom_line() used to display the lines corresponding to the centrality parameter.
ggplot.component: A ggplot component to be added to the plot prepared by {ggstatsplot}. This argument is primarily helpful for grouped_
variants of all primary functions. Default is NULL. The argument should be entered as a {ggplot2} function or a list of {ggplot2} functions.
...: Currently ignored.
For details, see: https://indrajeetpatil.github.io/ggstatsplot/articles/web_only/gghistostats.html
| graphical element | geom used | argument for further modification |
| histogram bin | ggplot2::stat_bin() | bin.args |
| centrality measure line | ggplot2::geom_vline() | centrality.line.args |
The table below provides summary about:
Hypothesis testing
| Type | Test | Function used |
| Parametric | One-sample Student's t -test | stats::t.test() |
| Non-parametric | One-sample Wilcoxon test | stats::wilcox.test() |
| Robust | Bootstrap- t method for one-sample test | WRS2::trimcibt() |
| Bayesian | One-sample Student's t -test | BayesFactor::ttestBF() |
Effect size estimation
| Type | Effect size | CI available? | Function used |
| Parametric | Cohen's d , Hedge's g | Yes | effectsize::cohens_d() , effectsize::hedges_g() |
| Non-parametric | r (rank-biserial correlation) | Yes | effectsize::rank_biserial() |
| Robust | trimmed mean | Yes | WRS2::trimcibt() |
| Bayes Factor | difference | Yes | bayestestR::describe_posterior() |
# for reproducibility set.seed(123) # creating a plot p <- gghistostats( data = ToothGrowth, x = len, xlab = "Tooth length", centrality.type = "np" ) # looking at the plot p # extracting details from statistical tests extract_stats(p)
grouped_gghistostats, ggdotplotstats, grouped_ggdotplotstats
Useful links