table1 function - RDocumentation (2024)

Produces a nicely formatted table of descriptive statistics for any numberof numeric or categorical variables, optionally stratified by a factor.

An object of class "table1".

There are two interfaces, the default, which typically takes a list ofdata.frames for x, and the formula interface. The formulainterface is less flexible, but simpler to use and designed to handle themost common use cases. It is important to use factors appropriately forcategorical variables (i.e. have the levels labeled properly and in thedesired order). The contents of the table can be customized by providinguser-defined `renderer' functions. Customization of the table appearance isdeliberately not attempted, as this is best accomplished with CSS. Tofacilitate this, some tags (such as row labels) are given specific classesfor easy CSS selection.

For the formula version, the formula is expected to be a one-sided formula,optionally with a vertical bar separating the variables that are to appearas data in the table (as rows) from those used for stratification (i.e.columns). There can be at most 2 variables for stratification (and only oneif transpose = TRUE is specified), and if 2 are specified, the secondis nested within the first. Stratification variables may not contain missingvalues. The formula may contain a dot (".") to refer to "all variables indata other than those that appear elsewhere in the formula". It islegitimate to use functions inside the formula to create new variables.

For the default version, is is expected that x is a namedlist of data.frames, one for each stratum, with names corresponding tostrata labels.

Extra columns can be added to the table using the extra.col argument.This is an optional named list of functions, with the names corresponding tothe column headings. Each function will be called once for each variableincluded in the table. Each function should expect 2 arguments, the firstbeing a list, the second the name of the variable. The contents of thelist passed in as the first argument will be the data associated with eachstratum in the table; i.e., one element for each normal column (not extracolumn). It is then up the function to compute the value to appear inthe extra column and return it as a string. By default, extra columns willbe placed to the far right, after the normal columns, in the order they arespecified in. This can be overridden, however, using theextra.col.pos vector of integer positions. For example, to place thefirst extra column in position 1 (far left), and the second extra column inposition 3, use extra.col.pos = c(1, 3); any extra columns that arenot assigned positions will be placed to the far right. A typical use casefor extra columns would be a column of p-values for differences betweenstrata. Note that this feature is not available when the optiontranspose = TRUE is specified.