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The goal of formatstats is to provide functions that flexibly format statistical output in a way that can be inserted into R Markdown or Quarto documents. This is analogous to the apa_print() functions in the {papaja} package, but functions in formatstats can print Markdown or LaTeX syntax. If your output document is a PDF, this doesn’t matter. But if your output document is a Word document (as required by many journal publishers), Markdown syntax generates editable output instead of an image of output. The default style for statistical output follows American Psychological Association style, but many defaults can be over-ridden to flexibly format output.

Installation

You can install the development version of formatstats from GitHub with:

# install.packages("remotes")
remotes::install_github("JeffreyRStevens/formatstats")

Example

For an example, we’ll create a correlation from the mtcars data set.

library(formatstats)
(cars_corr <- cor.test(mtcars$mpg, mtcars$disp))
#> 
#>  Pearson's product-moment correlation
#> 
#> data:  mtcars$mpg and mtcars$disp
#> t = -8.7472, df = 30, p-value = 9.38e-10
#> alternative hypothesis: true correlation is not equal to 0
#> 95 percent confidence interval:
#>  -0.9233594 -0.7081376
#> sample estimates:
#>        cor 
#> -0.8475514

Now we can apply the format_corr() function to cars_corr to create a Markdown-formatted character string for the statistical results. We can embed this as inline R Markdown code to generate the results.

Code

Fuel efficiency and engine displacement were highly correlated (`r format_corr(cars_corr)`).

Output

Fuel efficiency and engine displacement were highly correlated (r = -.85, 95% CI [-0.92, -0.71], p < .001).

Control formatting

We can also alter the output to allow other formatting. For instance, we may not like APA’s silly rule to remove leading zeros before a value that cannot exceed 1 (like correlations and p-values). And we may not want to include the confidence limits around the correlation coefficient. Finally, maybe we don’t want the statistics labels to be italicized.

Code

Fuel efficiency and engine displacement were highly correlated (`r format_corr(cars_corr, pzero = TRUE, ci = FALSE, italics = FALSE)`).

Output

Fuel efficiency and engine displacement were highly correlated (r = -0.85, p < 0.001).

Formatting types

  • Correlations (output from cor.test(), including Pearson’s, Kendall’s, and Spearman’s correlations)
  • Student t-tests and Wilcoxon rank sum and signed rank tests (output from t.test() and wilcox.test(), including one-sample, two-sample independent, and paired tests)
  • Means and error (calculates from vector or uses vector of mean and error interval or mean, lower error limit, and upper error limit)
  • P-values
  • Bayes factors (output from BayesFactor objects or scalar number)
  • Scientific notation
  • Other numbers

Citation

To cite formatstats, use:

Stevens, Jeffrey R. (2024). formatstats: Format and print statistical output. (version 0.0.0.9000) https://github.com/JeffreyRStevens/formatstats

  • papaja - This package uses the apa_print() function to convert a number of R statistical objects into R Markdown output. However, it only outputs LaTeX syntax and only generates APA formatted output with minimal flexibility to alter the output.
  • apa - This package also converts some R statistical objects to R Markdown output. While it allows other output format such as Markdown, it also only generates APA formatted output with minimal flexibility to alter the output.