The fmtr package contains functions to format vectors and data frames.


The fmtr package helps format data frames, similar to the way datasets are formatted in SAS®. Formats are assigned to columns using a format attribute. Formats are then applied by calling the fdata function on the data frame. The fdata function returns a new data frame with the formats applied to each column as specified.

All functions in the fmtr package also work with tidyverse tibbles.

The fmtr package also contains a function named value for defining user-defined formats in a manner similar to SAS® formats.


The main functions included in the fmtr package are as follows:

  • fdata: Applies formatting to a dataframe.

  • fapply: Applies formatting to a vector.

  • fcat: Creates a format catalog.

  • value: Creates a new user-defined format.

  • formats: Helps assign format attributes to a data frame.

  • fattr: Helps assign formatting attributes to a vector.

Available Formats

The formats that can be used with fmtr include the following:

  • Formatting strings

  • Named vectors

  • Vectorized functions

  • User-defined formats

  • Formatting lists

A formatting string is a compact set of codes typically used for formatting dates and numbers. See FormattingStrings for a glossary of common formatting codes.

Named vectors map one string value to another string value.

Vectorized functions can be those created by the user or by a formatting function like those created with Base R or the scales package.

User-defined functions are those created by the fmtr value function. See value for additional details.

Formatting lists are lists which contain any of the above format types. The formatting lists allow the user to apply one of several formats to the column. Formatting lists may also be used to apply different formats to each item in a vector. See flist for additional details on formatting lists.

See the fapply function documentation for additional details on applying formats.

Formats can be collected and stored as a single file, called a format catalog. This functionality makes it easy to reuse formats in new programs, with new data, or to share them with colleagues. See the fcat function for additional information.