github tidyverse/dplyr v1.1.0
dplyr 1.1.0

latest releases: v1.1.4, v1.1.3, v1.1.2...
18 months ago

New features

  • .by/by is an
    experimental alternative to group_by() that supports per-operation grouping
    for mutate(), summarise(), filter(), and the slice() family (#6528).

    Rather than:

    starwars %>%
      group_by(species, homeworld) %>%
      summarise(mean_height = mean(height))
    

    You can now write:

    starwars %>%
      summarise(
        mean_height = mean(height),
        .by = c(species, homeworld)
      )
    

    The most useful reason to do this is because .by only affects a single
    operation. In the example above, an ungrouped data frame went into the
    summarise() call, so an ungrouped data frame will come out; with .by, you
    never need to remember to ungroup() afterwards and you never need to use
    the .groups argument.

    Additionally, using summarise() with .by will never sort the results by
    the group key, unlike with group_by(). Instead, the results are returned
    using the existing ordering of the groups from the original data. We feel this
    is more predictable, better maintains any ordering you might have already
    applied with a previous call to arrange(), and provides a way to maintain
    the current ordering without having to resort to factors.

    This feature was inspired by
    data.table, where the
    equivalent syntax looks like:

    starwars[, .(mean_height = mean(height)), by = .(species, homeworld)]
    

    with_groups() is superseded in favor of .by (#6582).

  • reframe() is a new experimental verb that creates a new data frame by
    applying functions to columns of an existing data frame. It is very similar to
    summarise(), with two big differences:

    • reframe() can return an arbitrary number of rows per group, while
      summarise() reduces each group down to a single row.

    • reframe() always returns an ungrouped data frame, while summarise()
      might return a grouped or rowwise data frame, depending on the scenario.

    reframe() has been added in response to valid concern from the community
    that allowing summarise() to return any number of rows per group increases
    the chance for accidental bugs. We still feel that this is a powerful
    technique, and is a principled replacement for do(), so we have moved these
    features to reframe() (#6382).

  • group_by() now uses a new algorithm for computing groups. It is often faster
    than the previous approach (especially when there are many groups), and in
    most cases there should be no changes. The one exception is with character
    vectors, see the C locale news bullet below for more details (#4406, #6297).

  • arrange() now uses a faster algorithm for sorting character vectors, which
    is heavily inspired by data.table's forder(). See the C locale news bullet
    below for more details (#4962).

  • Joins have been completely overhauled to enable more flexible join operations
    and provide more tools for quality control. Many of these changes are inspired
    by data.table's join syntax (#5914, #5661, #5413, #2240).

    • A join specification can now be created through join_by(). This allows
      you to specify both the left and right hand side of a join using unquoted
      column names, such as join_by(sale_date == commercial_date). Join
      specifications can be supplied to any *_join() function as the by
      argument.

    • Join specifications allow for new types of joins:

      • Equality joins: The most common join, specified by ==. For example,
        join_by(sale_date == commercial_date).

      • Inequality joins: For joining on inequalities, i.e.>=, >, <, and
        <=. For example, use join_by(sale_date >= commercial_date) to find
        every commercial that aired before a particular sale.

      • Rolling joins: For "rolling" the closest match forward or backwards when
        there isn't an exact match, specified by using the rolling helper,
        closest(). For example,
        join_by(closest(sale_date >= commercial_date)) to find only the most
        recent commercial that aired before a particular sale.

      • Overlap joins: For detecting overlaps between sets of columns, specified
        by using one of the overlap helpers: between(), within(), or
        overlaps(). For example, use
        join_by(between(commercial_date, sale_date_lower, sale_date)) to
        find commercials that aired before a particular sale, as long as they
        occurred after some lower bound, such as 40 days before the sale was made.

      Note that you cannot use arbitrary expressions in the join conditions, like
      join_by(sale_date - 40 >= commercial_date). Instead, use mutate() to
      create a new column containing the result of sale_date - 40 and refer
      to that by name in join_by().

    • multiple is a new argument for controlling what happens when a row
      in x matches multiple rows in y. For equality joins and rolling joins,
      where this is usually surprising, this defaults to signalling a "warning",
      but still returns all of the matches. For inequality joins, where multiple
      matches are usually expected, this defaults to returning "all" of the
      matches. You can also return only the "first" or "last" match, "any"
      of the matches, or you can "error".

    • keep now defaults to NULL rather than FALSE. NULL implies
      keep = FALSE for equality conditions, but keep = TRUE for inequality
      conditions, since you generally want to preserve both sides of an
      inequality join.

    • unmatched is a new argument for controlling what happens when a row
      would be dropped because it doesn't have a match. For backwards
      compatibility, the default is "drop", but you can also choose to
      "error" if dropped rows would be surprising.

  • across() gains an experimental .unpack argument to optionally unpack
    (as in, tidyr::unpack()) data frames returned by functions in .fns
    (#6360).

  • consecutive_id() for creating groups based on contiguous runs of the
    same values, like data.table::rleid() (#1534).

  • case_match() is a "vectorised switch" variant of case_when() that matches
    on values rather than logical expressions. It is like a SQL "simple"
    CASE WHEN statement, whereas case_when() is like a SQL "searched"
    CASE WHEN statement (#6328).

  • cross_join() is a more explicit and slightly more correct replacement for
    using by = character() during a join (#6604).

  • pick() makes it easy to access a subset of columns from the current group.
    pick() is intended as a replacement for across(.fns = NULL), cur_data(),
    and cur_data_all(). We feel that pick() is a much more evocative name when
    you are just trying to select a subset of columns from your data (#6204).

  • symdiff() computes the symmetric difference (#4811).

Lifecycle changes

Breaking changes

  • arrange() and group_by() now use the C locale, not the system locale,
    when ordering or grouping character vectors. This brings substantial
    performance improvements, increases reproducibility across R sessions, makes
    dplyr more consistent with data.table, and we believe it should affect little
    existing code. If it does affect your code, you can use
    options(dplyr.legacy_locale = TRUE) to quickly revert to the previous
    behavior. However, in general, we instead recommend that you use the new
    .locale argument to precisely specify the desired locale. For a full
    explanation please read the associated
    grouping
    and ordering
    tidyups.

  • bench_tbls(), compare_tbls(), compare_tbls2(), eval_tbls(),
    eval_tbls2(), location() and changes(), deprecated in 1.0.0, are now
    defunct (#6387).

  • frame_data(), data_frame_(), lst_() and tbl_sum() are no longer
    re-exported from tibble (#6276, #6277, #6278, #6284).

  • select_vars(), rename_vars(), select_var() and current_vars(),
    deprecated in 0.8.4, are now defunct (#6387).

Newly deprecated

  • across(), c_across(), if_any(), and if_all() now require the
    .cols and .fns arguments. In general, we now recommend that you use
    pick() instead of an empty across() call or across() with no .fns
    (e.g. across(c(x, y)). (#6523).

    • Relying on the previous default of .cols = everything() is deprecated.
      We have skipped the soft-deprecation stage in this case, because indirect
      usage of across() and friends in this way is rare.

    • Relying on the previous default of .fns = NULL is not yet formally
      soft-deprecated, because there was no good alternative until now, but it is
      discouraged and will be soft-deprecated in the next minor release.

  • Passing ... to across() is soft-deprecated because it's ambiguous when
    those arguments are evaluated. Now, instead of (e.g.)
    across(a:b, mean, na.rm = TRUE) you should write
    across(a:b, ~ mean(.x, na.rm = TRUE)) (#6073).

  • all_equal() is deprecated. We've advised against it for some time, and
    we explicitly recommend you use all.equal(), manually reordering the rows
    and columns as needed (#6324).

  • cur_data() and cur_data_all() are soft-deprecated in favour of
    pick() (#6204).

  • Using by = character() to perform a cross join is now soft-deprecated in
    favor of cross_join() (#6604).

  • filter()ing with a 1-column matrix is deprecated (#6091).

  • progress_estimate() is deprecated for all uses (#6387).

  • Using summarise() to produce a 0 or >1 row "summary" is deprecated in favor
    of the new reframe(). See the NEWS bullet about reframe() for more details
    (#6382).

  • All functions deprecated in 1.0.0 (released April 2020) and earlier now warn
    every time you use them (#6387). This includes combine(), src_local(),
    src_mysql(), src_postgres(), src_sqlite(), rename_vars_(),
    select_vars_(), summarise_each_(), mutate_each_(), as.tbl(),
    tbl_df(), and a handful of older arguments. They are likely to be made
    defunct in the next major version (but not before mid 2024).

  • slice()ing with a 1-column matrix is deprecated.

Newly superseded

  • recode() is superseded in favour of case_match() (#6433).

  • recode_factor() is superseded. We don't have a direct replacement for it
    yet, but we plan to add one to forcats. In the meantime you can often use
    case_match(.ptype = factor(levels = )) instead (#6433).

  • transmute() is superseded in favour of mutate(.keep = "none") (#6414).

Newly stable

  • The .keep, .before, and .after arguments to mutate() have moved
    from experimental to stable.

  • The rows_*() family of functions have moved from experimental to stable.

vctrs

Many of dplyr's vector functions have been rewritten to make use of the vctrs
package, bringing greater consistency and improved performance.

  • between() can now work with all vector types, not just numeric and
    date-time. Additionally, left and right can now also be vectors (with the
    same length as x), and x, left, and right are cast to the common type
    before the comparison is made (#6183, #6260, #6478).

  • case_when() (#5106):

    • Has a new .default argument that is intended to replace usage of
      TRUE ~ default_value as a more explicit and readable way to specify
      a default value. In the future, we will deprecate the unsafe recycling of
      the LHS inputs that allows TRUE ~ to work, so we encourage you to switch
      to using .default.

    • No longer requires exact matching of the types of RHS values. For example,
      the following no longer requires you to use NA_character_.

      x <- c("little", "unknown", "small", "missing", "large")
      
      case_when(
        x %in% c("little", "small") ~ "one",
        x %in% c("big", "large") ~ "two",
        x %in% c("missing", "unknown") ~ NA
      )
      
    • Supports a larger variety of RHS value types. For example, you can use a
      data frame to create multiple columns at once.

    • Has new .ptype and .size arguments which allow you to enforce
      a particular output type and size.

    • Has a better error when types or lengths were incompatible (#6261, #6206).

  • coalesce() (#6265):

    • Discards NULL inputs up front.

    • No longer iterates over the columns of data frame input. Instead, a row is
      now only coalesced if it is entirely missing, which is consistent with
      vctrs::vec_detect_missing() and greatly simplifies the implementation.

    • Has new .ptype and .size arguments which allow you to enforce
      a particular output type and size.

  • first(), last(), and nth() (#6331):

    • When used on a data frame, these functions now return a single row rather
      than a single column. This is more consistent with the vctrs principle that
      a data frame is generally treated as a vector of rows.

    • The default is no longer "guessed", and will always automatically be set
      to a missing value appropriate for the type of x.

    • Error if n is not an integer. nth(x, n = 2) is fine, but
      nth(x, n = 2.5) is now an error.

    Additionally, they have all gained an na_rm argument since they
    are summary functions (#6242, with contributions from @tnederlof).

  • if_else() gains most of the same benefits as case_when(). In particular,
    if_else() now takes the common type of true, false, and missing to
    determine the output type, meaning that you can now reliably use NA,
    rather than NA_character_ and friends (#6243).

  • na_if() (#6329) now casts y to the type of x before comparison, which
    makes it clearer that this function is type and size stable on x. In
    particular, this means that you can no longer do na_if(<tibble>, 0), which
    previously accidentally allowed you to replace any instance of 0 across
    every column of the tibble with NA. na_if() was never intended to work
    this way, and this is considered off-label usage.

    You can also now replace NaN values in x with na_if(x, NaN).

  • lag() and lead() now cast default to the type of x, rather than taking
    the common type. This ensures that these functions are type stable on x
    (#6330).

  • row_number(), min_rank(), dense_rank(), ntile(), cume_dist(), and
    percent_rank() are faster and work for more types. You can now rank by
    multiple columns by supplying a data frame (#6428).

  • with_order() now checks that the size of order_by is the same size as x,
    and now works correctly when order_by is a data frame (#6334).

Minor improvements and bug fixes

  • Fixed an issue with latest rlang that caused internal tools (such as
    mask$eval_all_summarise()) to be mentioned in error messages (#6308).

  • Warnings are enriched with contextualised information in summarise() and
    filter() just like they have been in mutate() and arrange().

  • Joins now reference the correct column in y when a type error is thrown
    while joining on two columns with different names (#6465).

  • Joins on very wide tables are no longer bottlenecked by the application of
    suffix (#6642).

  • *_join() now error if you supply them with additional arguments that
    aren't used (#6228).

  • across() used without functions inside a rowwise-data frame no longer
    generates an invalid data frame (#6264).

  • Anonymous functions supplied with function() and \() are now inlined by
    across() if possible, which slightly improves performance and makes possible
    further optimisations in the future.

  • Functions supplied to across() are no longer masked by columns (#6545). For
    instance, across(1:2, mean) will now work as expected even if there is a
    column called mean.

  • across() will now error when supplied ... without a .fns argument
    (#6638).

  • arrange() now correctly ignores NULL inputs (#6193).

  • arrange() now works correctly when across() calls are used as the 2nd
    (or more) ordering expression (#6495).

  • arrange(df, mydesc::desc(x)) works correctly when mydesc re-exports
    dplyr::desc() (#6231).

  • c_across() now evaluates all_of() correctly and no longer allows you to
    accidentally select grouping variables (#6522).

  • c_across() now throws a more informative error if you try to rename during
    column selection (#6522).

  • dplyr no longer provides count() and tally() methods for tbl_sql.
    These methods have been accidentally overriding the tbl_lazy methods that
    dbplyr provides, which has resulted in issues with the grouping structure of
    the output (#6338, tidyverse/dbplyr#940).

  • cur_group() now works correctly with zero row grouped data frames (#6304).

  • desc() gives a useful error message if you give it a non-vector (#6028).

  • distinct() now retains attributes of bare data frames (#6318).

  • distinct() returns columns ordered the way you request, not the same
    as the input data (#6156).

  • Error messages in group_by(), distinct(), tally(), and count() are now
    more relevant (#6139).

  • group_by_prepare() loses the caller_env argument. It was rarely used
    and it is no longer needed (#6444).

  • group_walk() gains an explict .keep argument (#6530).

  • Warnings emitted inside mutate() and variants are now collected and stashed
    away. Run the new last_dplyr_warnings() function to see the warnings emitted
    within dplyr verbs during the last top-level command.

    This fixes performance issues when thousands of warnings are emitted with
    rowwise and grouped data frames (#6005, #6236).

  • mutate() behaves a little better with 0-row rowwise inputs (#6303).

  • A rowwise mutate() now automatically unlists list-columns containing
    length 1 vectors (#6302).

  • nest_join() has gained the na_matches argument that all other joins have.

  • nest_join() now preserves the type of y (#6295).

  • n_distinct() now errors if you don't give it any input (#6535).

  • nth(), first(), last(), and with_order() now sort character order_by
    vectors in the C locale. Using character vectors for order_by is rare, so we
    expect this to have little practical impact (#6451).

  • ntile() now requires n to be a single positive integer.

  • relocate() now works correctly with empty data frames and when .before or
    .after result in empty selections (#6167).

  • relocate() no longer drops attributes of bare data frames (#6341).

  • relocate() now retains the last name change when a single column is renamed
    multiple times while it is being moved. This better matches the behavior of
    rename() (#6209, with help from @eutwt).

  • rename() now contains examples of using all_of() and any_of() to rename
    using a named character vector (#6644).

  • rename_with() now disallows renaming in the .cols tidy-selection (#6561).

  • rename_with() now checks that the result of .fn is the right type and size
    (#6561).

  • rows_insert() now checks that y contains the by columns (#6652).

  • setequal() ignores differences between freely coercible types (e.g. integer
    and double) (#6114) and ignores duplicated rows (#6057).

  • slice() helpers again produce output equivalent to slice(.data, 0) when
    the n or prop argument is 0, fixing a bug introduced in the previous
    version (@eutwt, #6184).

  • slice() with no inputs now returns 0 rows. This is mostly for theoretical
    consistency (#6573).

  • slice() now errors if any expressions in ... are named. This helps avoid
    accidentally misspelling an optional argument, such as .by (#6554).

  • slice_*() now requires n to be an integer.

  • slice_*() generics now perform argument validation. This should make
    methods more consistent and simpler to implement (#6361).

  • slice_min() and slice_max() can order_by multiple variables if you
    supply them as a data.frame or tibble (#6176).

  • slice_min() and slice_max() now consistently include missing values in
    the result if necessary (i.e. there aren't enough non-missing values to
    reach the n or prop you have selected). If you don't want missing values
    to be included at all, set na_rm = TRUE (#6177).

  • slice_sample() now accepts negative n and prop values (#6402).

  • slice_sample() returns a data frame or group with the same number of rows as
    the input when replace = FALSE and n is larger than the number of rows or
    prop is larger than 1. This reverts a change made in 1.0.8, returning to the
    behavior of 1.0.7 (#6185)

  • slice_sample() now gives a more informative error when replace = FALSE and
    the number of rows requested in the sample exceeds the number of rows in the
    data (#6271).

  • storms has been updated to include 2021 data and some missing storms that
    were omitted due to an error (@steveharoz, #6320).

  • summarise() now correctly recycles named 0-column data frames (#6509).

  • union_all(), like union(), now requires that data frames be compatible:
    i.e. they have the same columns, and the columns have compatible types.

  • where() is re-exported from tidyselect (#6597).

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