forcats 1.0.1

• fct_cross() now varies the levels in the last factor fastest (@Adam-AKong, #373).
• Functions that create a new factor (e.g. lvls_expand(), lvls_reorder(), fct_lump_n(), fct_drop()) now preserves the class of the original object in addition to the attributes (#83).
• forcats now requires R 4.1.

forcats 1.0.0

New features

• New fct_na_value_to_level() and fct_na_level_to_value() to convert NA values to NA levels and vice versa (#337).

Minor improvement and bug fixes

• All functions now validate their inputs, giving more useful errors if you accidentally misspecify an input.

• fct_collapse() can now use other_level = NA (#291).

• fct_count() works with factors that contain NAs in levels.

• fct_explicit_na() is deprecated in favour of fct_na_value_to_level().

• fct_expand() gains an after argument so that you can choose where the new levels are placed (#138).

• fct_infreq() gains the ability to weight by another variable using the w argument (#261).

• fct_inorder() now works when not all levels appear in the data (#262).

• fct_lump_prop() and friends now work correctly if you supply weights and have empty levels (#292).

• fct_lump_n() and fct_lump_prop() will now create an “Other” level even if it only consists of a single level. This makes them consistent with the other fct_lump_* functions (#274).

• fct_other() no longer generates a warning if no levels are replaced with other (#265).

• fct_relevel(), fct_cross(), and fct_expand() now error if you name the arguments in ... since those names are ignored and your code probably doesn’t do what you think it does (#319).

• fct_reorder() and fct_reorder2() now remove NA values in .x with a warning (like ggplot2::geom_point() and friends). You can suppress the warning by setting .na_rm = TRUE (#315).

• fct_reorder() and fct_reorder2() gain a new .default argument that controls the placement of empty levels (including levels that might become empty after removing missing values in .x) (#266).

• fct_unique() now captures implicit missing values if present (#293).

forcats 0.5.2

• New fct() which works like factor() but errors if values of x are not included in the levels specification (#299)

• first2() and last2() now ignore missing values in both x and y (#303).

• Error messages are more informative.

forcats 0.5.1

• Re-license as MIT (#277).

• fct_lump_n() no longer uses a partial argument name (@malcolmbarrett, #276).

forcats 0.5.0

• as_factor() gains a logical method that always returns a factor with levels “FALSE” and “TRUE” (#185).

• fct_c(), fct_collapse() and fct_recode() are now explicitly documented as using dynamic dots (@labouz, #234).

• fct_collapse() now accepts a other_level argument, to allow a user-specified Other level (@gtm19, #194). It now correctly collapses factors when other_level is not NULL (#172), and makes "Other" the last level (#202) (@gtm19, #172 & #202)

• fct_count() no longer converts implicit NAs into explicit NAs (#151).

• fct_inseq() behaves more robustly when factor levels aren’t all numbers (#221).

• fct_lump() has been split up into three new functions: fct_lump_prop(), fct_lump_n(), and fct_lump_lowfreq(). (@jonocarroll, #167, #142). All fct_lump_() functions check their inputs more carefully (@robinson_es, #169)

• fct_reorder2() gains a helper function first2(), that sorts .y by the first value of .x (@jtr13).

forcats 0.4.0

New features

• fct_collapse() gains a group_other argument to allow you to group all un-named levels into "Other". (#100, @AmeliaMN)

• fct_cross() creates a new factor containing the combined levels from two or more input factors, similar to base::interaction (@tslumley, #136)

• fct_inseq() reorders labels in numeric order, if possible (#145, @kbodwin).

• fct_lump_min() preserves levels that appear at least min times (can also be used with the w weighted argument) (@robinsones, #142).

• fct_match() performs validated matching, providing a safer alternative to f %in% c("x", "y") which silently returns FALSE if "x" or "y" are not levels of f (e.g. because of a typo) (#126, @jonocarroll).

• fct_relevel() can now level factors using a function that is passed the current levels (#117).

• as_factor() now has a numeric method. By default, orders factors in numeric order, unlike the other methods which default to order of appearance. (#145, @kbodwin)

Minor bug fixes and improvements

• fct_count() gains a parameter to also compute the proportion (@zhiiiyang, #146).

• fct_lump() now does not change the label if no lumping occurs (@zhiiiyang, #130).

• fct_relabel() now accepts character input.

• fct_reorder() and fct_reorder2() no longer require that the summary function return a numeric vector of length 1; instead it can return any orderable vector of length 1 (#147).

• fct_reorder(), fct_reorder2() and as_factor() now use the ellipsis package to warn if you pass in named components to ... (#174).

forcats 0.3.0

API changes

• fct_c() now requires explicit splicing with !!! if you have a list of factors that you want to combine. This is consistent with an emerging standards for handling ... throughout the tidyverse.

• fct_reorder() and fct_reorder2() have renamed fun to .fun to avoid spurious matching of named arguments.

New features

• All functions that take ... use “tidy” dots: this means that you use can !!! to splice in a list of values, and trailing empty arguments are automatically removed. Additionally, all other arguments gain a . prefix in order to avoid unhelpful matching of named arguments (#110).

• fct_lump() gains w argument (#70, @wilkox) to weight value frequencies before lumping them together (#68).

Improvements to NA handling

• as_factor() and fct_inorder() accept NA levels (#98).

• fct_explicit_na() also replaces NAs encoded in levels.

• fct_lump() correctly accounts for NA values in input (#41)

• lvls_revalue() preserves NA levels.

Minor improvements and bug fixes

• Test coverage increased from 80% to 99%.

• fct_drop() now preserves attributes (#83).

• fct_expand() and lvls_expand() now also take character vectors (#99).

• fct_relabel() now accepts objects coercible to functions by rlang::as_function (#91, @alistaire47)

forcats 0.2.0

New functions

• as_factor() which works like as.factor() but orders levels by appearance to avoid differences between locales (#39).

• fct_other() makes it easier to convert selected levels to “other” (#40)

• fct_relabel() allows programmatic relabeling of levels (#50, @krlmlr).

Minor improvements and bug fixes

• fct_c() can take either a list of factors or individual factors (#42).

• fct_drop() gains only argument to restrict which levels are dropped (#69) and no longer adds NA level if not present (#52).

• fct_recode() is now checks that each new value is of length 1 (#56).

• fct_relevel() gains after argument so you can also move levels to the end (or any other position you like) (#29).

• lvls_reorder(), fct_inorder(), and fct_infreq() gain an ordered argument, allowing you to override the existing “ordered” status (#54).

forcats 0.1.1

• Minor fixes for R CMD check

• Add package docs