New features
-
.by
/by
is an
experimental alternative togroup_by()
that supports per-operation grouping
formutate()
,summarise()
,filter()
, and theslice()
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 toungroup()
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 withgroup_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 toarrange()
, 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is superseded in favor of.by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, whilesummarise()
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 allowingsummarise()
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 fordo()
, so we have moved these
features toreframe()
(#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'sforder()
. 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 asjoin_by(sale_date == commercial_date)
. Join
specifications can be supplied to any*_join()
function as theby
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, usejoin_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, usemutate()
to
create a new column containing the result ofsale_date - 40
and refer
to that by name injoin_by()
. -
-
multiple
is a new argument for controlling what happens when a row
inx
matches multiple rows iny
. 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 toNULL
rather thanFALSE
.NULL
implies
keep = FALSE
for equality conditions, butkeep = 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, likedata.table::rleid()
(#1534). -
case_match()
is a "vectorised switch" variant ofcase_when()
that matches
on values rather than logical expressions. It is like a SQL "simple"
CASE WHEN
statement, whereascase_when()
is like a SQL "searched"
CASE WHEN
statement (#6328). -
cross_join()
is a more explicit and slightly more correct replacement for
usingby = 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 foracross(.fns = NULL)
,cur_data()
,
andcur_data_all()
. We feel thatpick()
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()
andgroup_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()
andchanges()
, deprecated in 1.0.0, are now
defunct (#6387). -
frame_data()
,data_frame_()
,lst_()
andtbl_sum()
are no longer
re-exported from tibble (#6276, #6277, #6278, #6284). -
select_vars()
,rename_vars()
,select_var()
andcurrent_vars()
,
deprecated in 0.8.4, are now defunct (#6387).
Newly deprecated
-
across()
,c_across()
,if_any()
, andif_all()
now require the
.cols
and.fns
arguments. In general, we now recommend that you use
pick()
instead of an emptyacross()
call oracross()
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 ofacross()
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
...
toacross()
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 useall.equal()
, manually reordering the rows
and columns as needed (#6324). -
cur_data()
andcur_data_all()
are soft-deprecated in favour of
pick()
(#6204). -
Using
by = character()
to perform a cross join is now soft-deprecated in
favor ofcross_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 newreframe()
. See the NEWS bullet aboutreframe()
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 includescombine()
,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 ofcase_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 ofmutate(.keep = "none")
(#6414).
Newly stable
-
The
.keep
,.before
, and.after
arguments tomutate()
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
andright
can now also be vectors (with the
same length asx
), andx
,left
, andright
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 allowsTRUE ~
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 useNA_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()
, andnth()
(#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 ofx
. -
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 ascase_when()
. In particular,
if_else()
now takes the common type oftrue
,false
, andmissing
to
determine the output type, meaning that you can now reliably useNA
,
rather thanNA_character_
and friends (#6243). -
na_if()
(#6329) now castsy
to the type ofx
before comparison, which
makes it clearer that this function is type and size stable onx
. In
particular, this means that you can no longer dona_if(<tibble>, 0)
, which
previously accidentally allowed you to replace any instance of0
across
every column of the tibble withNA
.na_if()
was never intended to work
this way, and this is considered off-label usage.You can also now replace
NaN
values inx
withna_if(x, NaN)
. -
lag()
andlead()
now castdefault
to the type ofx
, rather than taking
the common type. This ensures that these functions are type stable onx
(#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 oforder_by
is the same size asx
,
and now works correctly whenorder_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 inmutate()
andarrange()
. -
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 calledmean
. -
across()
will now error when supplied...
without a.fns
argument
(#6638). -
arrange()
now correctly ignoresNULL
inputs (#6193). -
arrange()
now works correctly whenacross()
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 evaluatesall_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()
andtally()
methods fortbl_sql
.
These methods have been accidentally overriding thetbl_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()
, andcount()
are now
more relevant (#6139). -
group_by_prepare()
loses thecaller_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 newlast_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 thena_matches
argument that all other joins have. -
nest_join()
now preserves the type ofy
(#6295). -
n_distinct()
now errors if you don't give it any input (#6535). -
nth()
,first()
,last()
, andwith_order()
now sort characterorder_by
vectors in the C locale. Using character vectors fororder_by
is rare, so we
expect this to have little practical impact (#6451). -
ntile()
now requiresn
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 usingall_of()
andany_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 thaty
contains theby
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 toslice(.data, 0)
when
then
orprop
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 requiresn
to be an integer. -
slice_*()
generics now perform argument validation. This should make
methods more consistent and simpler to implement (#6361). -
slice_min()
andslice_max()
canorder_by
multiple variables if you
supply them as a data.frame or tibble (#6176). -
slice_min()
andslice_max()
now consistently include missing values in
the result if necessary (i.e. there aren't enough non-missing values to
reach then
orprop
you have selected). If you don't want missing values
to be included at all, setna_rm = TRUE
(#6177). -
slice_sample()
now accepts negativen
andprop
values (#6402). -
slice_sample()
returns a data frame or group with the same number of rows as
the input whenreplace = FALSE
andn
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 whenreplace = 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()
, likeunion()
, 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).