The arsenal Package

The goal of library(arsenal) is to make statistical reporting easy. It includes many functions which the useR will find useful to have in his/her "arsenal" of functions. There are, at this time, 5 main functions, documented below. Each of these functions is motivated by a local SAS macro or procedure of similar functionality.

The tableby() Function

tableby() is a function to easily summarize a set of independent variables by a categorical variable. Optionally, an appropriate test is performed to test the distribution of the independent variables across the levels of the categorical variable. Options for this function are easily controled using tableby.control().

The tableby() output is easily knitted in an Rmarkdown document or displayed in the command line using the summary() function. Other S3 methods are implemented for objects of class "tableby", including print(), [, as.data.frame(), and merge().

The modelsum() Function

modelsum() is a function to fit and summarize models for each independent variable with a response variable, with options to adjust by variables for each model. Options for this function are easily controled using modelsum.control().

The modelsum output is easily knitted in an Rmarkdown document or displayed in the command line using the summary() function. Other S3 methods are implemented for objects of class "modelsum", including print() and as.data.frame().

The freqlist() Function

freqlist() is a function to approximate the output from SAS's PROC FREQ procedure when using the /list option of the TABLE statement.

The freqlist() output is easily knitted in an Rmarkdown document or displayed in the command line using the summary() function. Other S3 methods are implemented for objects of class "freqlist", including print() and as.data.frame().

The compare.data.frame() Function

compare.data.frame() is the S3 method for comparing two data.frames and reporting any differences between them, much like SAS's PROC COMPARE procedure.

The compare.data.frame() output is easily nknitted in an Rmarkdown document or displayed in the command line using the summary() function. Other S3 methods are implemented for objects of class "compare.data.frame", including print() and diffs().

The write2*() Family of Functions

write2word(), write2pdf(), and write2html() are functions to output a table into a document, much like SAS's ODS procedure. The S3 method behind them is write2(). There are methods implemented for tableby(), modelsum(), and freqlist() and also methods for knitr::kable(), xtable::xtable(), and pander::pander_return(). Another option is to coerce an object using verbatim() to print out the results monospaced (as if they were in the terminal)--the default method does this automatically. To output multiple tables into a document, simply make a list of them and call the same function as before.

For more information, see vignette("write2").

Other Notable Functions

• keep.labels() keeps the 'label' attribute on an R object when subsetting.

• formulize() is a shortcut to collapse variable names into a formula.

• mdy.Date() and Date.mdy() convert numeric dates for month, day, and year to Date object, and vice versa.

• is.Date: tests if an object is a date.

• %nin% tests for "not in", the negation of %in%.