Package 'tidytable'

Title: Tidy Interface to 'data.table'
Description: A tidy interface to 'data.table', giving users the speed of 'data.table' while using tidyverse-like syntax.
Authors: Mark Fairbanks [aut, cre], Abdessabour Moutik [ctb], Matt Carlson [ctb], Ivan Leung [ctb], Ross Kennedy [ctb], Robert On [ctb], Alexander Sevostianov [ctb], Koen ter Berg [ctb]
Maintainer: Mark Fairbanks <[email protected]>
License: MIT + file LICENSE
Version: 0.11.1.9
Built: 2024-10-25 06:18:36 UTC
Source: https://github.com/markfairbanks/tidytable

Help Index


Fast %in% and ⁠%notin%⁠ operators

Description

Check whether values in a vector are in or not in another vector.

Built using data.table::'%chin%' and vctrs::vec_in() for performance.

Usage

x %in% y

x %notin% y

Arguments

x

A vector of values to check if they exist in y

y

A vector of values to check if x values exist in

Details

Falls back to base::'%in%' when x and y don't share a common type. This means that the behaviour of base::'%in%' is preserved (e.g. "1" %in% c(1, 2) is TRUE) but loses the speedup provided by vctrs::vec_in().

Examples

df <- tidytable(x = 1:4, y = 1:4)

df %>%
  filter(x %in% c(2, 4))

df %>%
  filter(x %notin% c(2, 4))

Apply a function across a selection of columns

Description

Apply a function across a selection of columns. For use in arrange(), mutate(), and summarize().

Usage

across(.cols = everything(), .fns = NULL, ..., .names = NULL)

Arguments

.cols

vector c() of unquoted column names. tidyselect compatible.

.fns

Function to apply. Can be a purrr-style lambda. Can pass also list of functions.

...

Other arguments for the passed function

.names

A glue specification that helps with renaming output columns. {.col} stands for the selected column, and {.fn} stands for the name of the function being applied. The default (NULL) is equivalent to "{.col}" for a single function case and "{.col}_{.fn}" when a list is used for .fns.

Examples

df <- data.table(
  x = rep(1, 3),
  y = rep(2, 3),
  z = c("a", "a", "b")
)

df %>%
  mutate(across(c(x, y), ~ .x * 2))

df %>%
  summarize(across(where(is.numeric), ~ mean(.x)),
            .by = z)

df %>%
  arrange(across(c(y, z)))

Add a count column to the data frame

Description

Add a count column to the data frame.

df %>% add_count(a, b) is equivalent to using df %>% mutate(n = n(), .by = c(a, b))

Usage

add_count(.df, ..., wt = NULL, sort = FALSE, name = NULL)

add_tally(.df, wt = NULL, sort = FALSE, name = NULL)

Arguments

.df

A data.frame or data.table

...

Columns to group by. tidyselect compatible.

wt

Frequency weights. Can be NULL or a variable:

  • If NULL (the default), counts the number of rows in each group.

  • If a variable, computes sum(wt) for each group.

sort

If TRUE, will show the largest groups at the top.

name

The name of the new column in the output.

If omitted, it will default to n.

Examples

df <- data.table(
  a = c("a", "a", "b"),
  b = 1:3
)

df %>%
  add_count(a)

Arrange/reorder rows

Description

Order rows in ascending or descending order.

Usage

arrange(.df, ...)

Arguments

.df

A data.frame or data.table

...

Variables to arrange by

Examples

df <- data.table(
  a = 1:3,
  b = 4:6,
  c = c("a", "a", "b")
)

df %>%
  arrange(c, -a)

df %>%
  arrange(c, desc(a))

Coerce an object to a data.table/tidytable

Description

A tidytable object is simply a data.table with nice printing features.

Note that all tidytable functions automatically convert data.frames & data.tables to tidytables in the background. As such this function will rarely need to be used by the user.

Usage

as_tidytable(x, ..., .name_repair = "unique", .keep_rownames = FALSE)

Arguments

x

An R object

...

Additional arguments to be passed to or from other methods.

.name_repair

Treatment of duplicate names. See ?vctrs::vec_as_names for options/details.

.keep_rownames

Default is FALSE. If TRUE, adds the input object's names as a separate column named "rn". .keep_rownames = "id" names the column "id" instead.

Examples

df <- data.frame(x = -2:2, y = c(rep("a", 3), rep("b", 2)))

df %>%
  as_tidytable()

Do the values from x fall between the left and right bounds?

Description

between() utilizes data.table::between() in the background

Usage

between(x, left, right)

Arguments

x

A numeric vector

left, right

Boundary values

Examples

df <- data.table(
  x = 1:5,
  y = 1:5
)

# Typically used in a filter()
df %>%
  filter(between(x, 2, 4))

df %>%
  filter(x %>% between(2, 4))

# Can also use the %between% operator
df %>%
  filter(x %between% c(2, 4))

Bind data.tables by row and column

Description

Bind multiple data.tables into one row-wise or col-wise.

Usage

bind_cols(..., .name_repair = "unique")

bind_rows(..., .id = NULL)

Arguments

...

data.tables or data.frames to bind

.name_repair

Treatment of duplicate names. See ?vctrs::vec_as_names for options/details.

.id

If TRUE, an integer column is made as a group id

Examples

# Binding data together by row
df1 <- data.table(x = 1:3, y = 10:12)
df2 <- data.table(x = 4:6, y = 13:15)

df1 %>%
  bind_rows(df2)

# Can pass a list of data.tables
df_list <- list(df1, df2)

bind_rows(df_list)

# Binding data together by column
df1 <- data.table(a = 1:3, b = 4:6)
df2 <- data.table(c = 7:9)

df1 %>%
  bind_cols(df2)

# Can pass a list of data frames
bind_cols(list(df1, df2))

Combine values from multiple columns

Description

c_across() works inside of mutate_rowwise(). It uses tidyselect so you can easily select multiple variables.

Usage

c_across(cols = everything())

Arguments

cols

Columns to transform.

Examples

df <- data.table(x = runif(6), y = runif(6), z = runif(6))

df %>%
  mutate_rowwise(row_mean = mean(c_across(x:z)))

data.table::fcase() with vectorized default

Description

This function allows you to use multiple if/else statements in one call.

It is called like data.table::fcase(), but allows the user to use a vector as the default argument.

Usage

case(..., default = NA, ptype = NULL, size = NULL)

Arguments

...

Sequence of condition/value designations

default

Default value. Set to NA by default.

ptype

Optional ptype to specify the output type.

size

Optional size to specify the output size.

Examples

df <- tidytable(x = 1:10)

df %>%
  mutate(case_x = case(x < 5, 1,
                       x < 7, 2,
                       default = 3))

Vectorized switch()

Description

Allows the user to succinctly create a new vector based off conditions of a single vector.

Usage

case_match(.x, ..., .default = NA, .ptype = NULL)

Arguments

.x

A vector

...

A sequence of two-sided formulas. The left hand side gives the old values, the right hand side gives the new value.

.default

The default value if all conditions evaluate to FALSE.

.ptype

Optional ptype to specify the output type.

Examples

df <- tidytable(x = c("a", "b", "c", "d"))

df %>%
  mutate(
    case_x = case_match(x,
                        c("a", "b") ~ "new_1",
                        "c" ~ "new_2",
                        .default = x)
  )

Case when

Description

This function allows you to use multiple if/else statements in one call.

It is called like dplyr::case_when(), but utilizes data.table::fifelse() in the background for improved performance.

Usage

case_when(..., .default = NA, .ptype = NULL, .size = NULL)

Arguments

...

A sequence of two-sided formulas. The left hand side gives the conditions, the right hand side gives the values.

.default

The default value if all conditions evaluate to FALSE.

.ptype

Optional ptype to specify the output type.

.size

Optional size to specify the output size.

Examples

df <- tidytable(x = 1:10)

df %>%
  mutate(case_x = case_when(x < 5 ~ 1,
                            x < 7 ~ 2,
                            TRUE ~ 3))

Coalesce missing values

Description

Fill in missing values in a vector by pulling successively from other vectors.

Usage

coalesce(..., .ptype = NULL, .size = NULL)

Arguments

...

Input vectors. Supports dynamic dots.

.ptype

Optional ptype to override output type

.size

Optional size to override output size

Examples

# Use a single value to replace all missing values
x <- c(1:3, NA, NA)
coalesce(x, 0)

# Or match together a complete vector from missing pieces
y <- c(1, 2, NA, NA, 5)
z <- c(NA, NA, 3, 4, 5)
coalesce(y, z)

# Supply lists with dynamic dots
vecs <- list(
  c(1, 2, NA, NA, 5),
  c(NA, NA, 3, 4, 5)
)
coalesce(!!!vecs)

Complete a data.table with missing combinations of data

Description

Turns implicit missing values into explicit missing values.

Usage

complete(.df, ..., fill = list(), .by = NULL)

Arguments

.df

A data.frame or data.table

...

Columns to expand

fill

A named list of values to fill NAs with.

.by

Columns to group by

Examples

df <- data.table(x = 1:2, y = 1:2, z = 3:4)

df %>%
  complete(x, y)

df %>%
  complete(x, y, fill = list(z = 10))

Generate a unique id for consecutive values

Description

Generate a unique id for runs of consecutive values

Usage

consecutive_id(...)

Arguments

...

Vectors of values

Examples

x <- c(1, 1, 2, 2, 1, 1)
consecutive_id(x)

Context functions

Description

These functions give information about the "current" group.

  • cur_data() gives the current data for the current group

  • cur_column() gives the name of the current column (for use in across() only)

  • cur_group_id() gives a group identification number

  • cur_group_rows() gives the row indices for each group

Can be used inside summarize(), mutate(), & filter()

Usage

cur_column()

cur_data()

cur_group_id()

cur_group_rows()

Examples

df <- data.table(
  x = 1:5,
  y = c("a", "a", "a", "b", "b")
)

df %>%
  mutate(
    across(c(x, y), ~ paste(cur_column(), .x))
  )

df %>%
  summarize(data = list(cur_data()),
            .by = y)

df %>%
  mutate(group_id = cur_group_id(),
         .by = y)

df %>%
  mutate(group_rows = cur_group_rows(),
         .by = y)

Count observations by group

Description

Returns row counts of the dataset.

tally() returns counts by group on a grouped tidytable.

count() returns counts by group on a grouped tidytable, or column names can be specified to return counts by group.

Usage

count(.df, ..., wt = NULL, sort = FALSE, name = NULL)

tally(.df, wt = NULL, sort = FALSE, name = NULL)

Arguments

.df

A data.frame or data.table

...

Columns to group by in count(). tidyselect compatible.

wt

Frequency weights. tidyselect compatible. Can be NULL or a variable:

  • If NULL (the default), counts the number of rows in each group.

  • If a variable, computes sum(wt) for each group.

sort

If TRUE, will show the largest groups at the top.

name

The name of the new column in the output.

If omitted, it will default to n.

Examples

df <- data.table(
  x = c("a", "a", "b"),
  y = c("a", "a", "b"),
  z = 1:3
)

df %>%
  count()

df %>%
  count(x)

df %>%
  count(where(is.character))

df %>%
  count(x, wt = z, name = "x_sum")

df %>%
  count(x, sort = TRUE)

df %>%
  tally()

df %>%
  group_by(x) %>%
  tally()

Cross join

Description

Cross join each row of x to every row in y.

Usage

cross_join(x, y, ..., suffix = c(".x", ".y"))

Arguments

x

A data.frame or data.table

y

A data.frame or data.table

...

Other parameters passed on to methods

suffix

Append created for duplicated column names when using full_join()

Examples

df1 <- tidytable(x = 1:3)
df2 <- tidytable(y = 4:6)

cross_join(df1, df2)

Create a data.table from all unique combinations of inputs

Description

crossing() is similar to expand_grid() but de-duplicates and sorts its inputs.

Usage

crossing(..., .name_repair = "check_unique")

Arguments

...

Variables to get unique combinations of

.name_repair

Treatment of problematic names. See ?vctrs::vec_as_names for options/details

Examples

x <- 1:2
y <- 1:2

crossing(x, y)

crossing(stuff = x, y)

Descending order

Description

Arrange in descending order. Can be used inside of arrange()

Usage

desc(x)

Arguments

x

Variable to arrange in descending order

Examples

df <- data.table(
  a = 1:3,
  b = 4:6,
  c = c("a", "a", "b")
)

df %>%
  arrange(c, desc(a))

Select distinct/unique rows

Description

Retain only unique/distinct rows from an input df.

Usage

distinct(.df, ..., .keep_all = FALSE)

Arguments

.df

A data.frame or data.table

...

Columns to select before determining uniqueness. If omitted, will use all columns. tidyselect compatible.

.keep_all

Only relevant if columns are provided to ... arg. This keeps all columns, but only keeps the first row of each distinct values of columns provided to ... arg.

Examples

df <- tidytable(
  x = 1:3,
  y = 4:6,
  z = c("a", "a", "b")
)

df %>%
  distinct()

df %>%
  distinct(z)

Drop rows containing missing values

Description

Drop rows containing missing values

Usage

drop_na(.df, ...)

Arguments

.df

A data.frame or data.table

...

Optional: A selection of columns. If empty, all variables are selected. tidyselect compatible.

Examples

df <- data.table(
  x = c(1, 2, NA),
  y = c("a", NA, "b")
)

df %>%
  drop_na()

df %>%
  drop_na(x)

df %>%
  drop_na(where(is.numeric))

Pipeable data.table call

Description

Pipeable data.table call.

This function does not use data.table's modify-by-reference.

Has experimental support for tidy evaluation for custom functions.

Usage

dt(.df, i, j, ...)

Arguments

.df

A data.frame or data.table

i

i position of a data.table call. See ?data.table::data.table

j

j position of a data.table call. See ?data.table::data.table

...

Other arguments passed to data.table call. See ?data.table::data.table

Examples

df <- tidytable(
  x = 1:3,
  y = 4:6,
  z = c("a", "a", "b")
)

df %>%
  dt(, double_x := x * 2) %>%
  dt(order(-double_x))

# Experimental support for tidy evaluation for custom functions
add_one <- function(data, col) {
  data %>%
    dt(, new_col := {{ col }} + 1)
}

df %>%
  add_one(x)

Convert a vector to a data.table/tidytable

Description

Converts named and unnamed vectors to a data.table/tidytable.

Usage

enframe(x, name = "name", value = "value")

Arguments

x

A vector

name

Name of the column that stores the names. If name = NULL, a one-column tidytable will be returned.

value

Name of the column that stores the values.

Examples

vec <- 1:3
names(vec) <- letters[1:3]

enframe(vec)

Expand a data.table to use all combinations of values

Description

Generates all combinations of variables found in a dataset.

expand() is useful in conjunction with joins:

  • use with right_join() to convert implicit missing values to explicit missing values

  • use with anti_join() to find out which combinations are missing

nesting() is a helper that only finds combinations already present in the dataset.

Usage

expand(.df, ..., .name_repair = "check_unique", .by = NULL)

nesting(..., .name_repair = "check_unique")

Arguments

.df

A data.frame or data.table

...

Columns to get combinations of

.name_repair

Treatment of duplicate names. See ?vctrs::vec_as_names for options/details

.by

Columns to group by

Examples

df <- tidytable(x = c(1, 1, 2), y = c(1, 1, 2))

df %>%
  expand(x, y)

df %>%
  expand(nesting(x, y))

Create a data.table from all combinations of inputs

Description

Create a data.table from all combinations of inputs

Usage

expand_grid(..., .name_repair = "check_unique")

Arguments

...

Variables to get combinations of

.name_repair

Treatment of problematic names. See ?vctrs::vec_as_names for options/details

Examples

x <- 1:2
y <- 1:2

expand_grid(x, y)

expand_grid(stuff = x, y)

Extract a character column into multiple columns using regex

Description

Superseded

extract() has been superseded by separate_wider_regex().

Given a regular expression with capturing groups, extract() turns each group into a new column. If the groups don't match, or the input is NA, the output will be NA. When you pass same name in the into argument it will merge the groups together. Whilst passing NA in the into arg will drop the group from the resulting tidytable

Usage

extract(
  .df,
  col,
  into,
  regex = "([[:alnum:]]+)",
  remove = TRUE,
  convert = FALSE,
  ...
)

Arguments

.df

A data.table or data.frame

col

Column to extract from

into

New column names to split into. A character vector.

regex

A regular expression to extract the desired values. There should be one group (defined by ⁠()⁠) for each element of into

remove

If TRUE, remove the input column from the output data.table

convert

If TRUE, runs type.convert() on the resulting column. Useful if the resulting column should be type integer/double.

...

Additional arguments passed on to methods.

Examples

df <- data.table(x = c(NA, "a-b-1", "a-d-3", "b-c-2", "d-e-7"))
df %>% extract(x, "A")
df %>% extract(x, c("A", "B"), "([[:alnum:]]+)-([[:alnum:]]+)")

# If no match, NA:
df %>% extract(x, c("A", "B"), "([a-d]+)-([a-d]+)")
# drop columns by passing NA
df %>% extract(x, c("A", NA, "B"), "([a-d]+)-([a-d]+)-(\\d+)")
# merge groups by passing same name
df %>% extract(x, c("A", "B", "A"), "([a-d]+)-([a-d]+)-(\\d+)")

Fill in missing values with previous or next value

Description

Fills missing values in the selected columns using the next or previous entry. Can be done by group.

Supports tidyselect

Usage

fill(.df, ..., .direction = c("down", "up", "downup", "updown"), .by = NULL)

Arguments

.df

A data.frame or data.table

...

A selection of columns. tidyselect compatible.

.direction

Direction in which to fill missing values. Currently "down" (the default), "up", "downup" (first down then up), or "updown" (first up and then down)

.by

Columns to group by when filling should be done by group

Examples

df <- data.table(
  a = c(1, NA, 3, 4, 5),
  b = c(NA, 2, NA, NA, 5),
  groups = c("a", "a", "a", "b", "b")
)

df %>%
  fill(a, b)

df %>%
  fill(a, b, .by = groups)

df %>%
  fill(a, b, .direction = "downup", .by = groups)

Filter rows on one or more conditions

Description

Filters a dataset to choose rows where conditions are true.

Usage

filter(.df, ..., .by = NULL)

Arguments

.df

A data.frame or data.table

...

Conditions to filter by

.by

Columns to group by if filtering with a summary function

Examples

df <- tidytable(
  a = 1:3,
  b = 4:6,
  c = c("a", "a", "b")
)

df %>%
  filter(a >= 2, b >= 4)

df %>%
  filter(b <= mean(b), .by = c)

Extract the first, last, or nth value from a vector

Description

Extract the first, last, or nth value from a vector.

Note: These are simple wrappers around vctrs::vec_slice().

Usage

first(x, default = NULL, na_rm = FALSE)

last(x, default = NULL, na_rm = FALSE)

nth(x, n, default = NULL, na_rm = FALSE)

Arguments

x

A vector

default

The default value if the value doesn't exist.

na_rm

If TRUE ignores missing values.

n

For nth(), a number specifying the position to grab.

Examples

vec <- letters

first(vec)
last(vec)
nth(vec, 4)

Read/write files

Description

fread() is a simple wrapper around data.table::fread() that returns a tidytable instead of a data.table.

Usage

fread(...)

Arguments

...

Arguments passed on to data.table::fread

Examples

fake_csv <- "A,B
             1,2
             3,4"

fread(fake_csv)

Convert character and factor columns to dummy variables

Description

Convert character and factor columns to dummy variables

Usage

get_dummies(
  .df,
  cols = where(~is.character(.x) | is.factor(.x)),
  prefix = TRUE,
  prefix_sep = "_",
  drop_first = FALSE,
  dummify_na = TRUE
)

Arguments

.df

A data.frame or data.table

cols

A single column or a vector of unquoted columns to dummify. Defaults to all character & factor columns using c(where(is.character), where(is.factor)). tidyselect compatible.

prefix

TRUE/FALSE - If TRUE, a prefix will be added to new column names

prefix_sep

Separator for new column names

drop_first

TRUE/FALSE - If TRUE, the first dummy column will be dropped

dummify_na

TRUE/FALSE - If TRUE, NAs will also get dummy columns

Examples

df <- tidytable(
  chr = c("a", "b", NA),
  fct = as.factor(c("a", NA, "c")),
  num = 1:3
)

# Automatically does all character/factor columns
df %>%
  get_dummies()

df %>%
  get_dummies(cols = chr)

df %>%
  get_dummies(cols = c(chr, fct), drop_first = TRUE)

df %>%
  get_dummies(prefix_sep = ".", dummify_na = FALSE)

Grouping

Description

  • group_by() adds a grouping structure to a tidytable. Can use tidyselect syntax.

  • ungroup() removes grouping.

Usage

group_by(.df, ..., .add = FALSE)

ungroup(.df, ...)

Arguments

.df

A data.frame or data.table

...

Columns to group by

.add

Should grouping cols specified be added to the current grouping

Examples

df <- data.table(
  a = 1:3,
  b = 4:6,
  c = c("a", "a", "b"),
  d = c("a", "a", "b")
)

df %>%
  group_by(c, d) %>%
  summarize(mean_a = mean(a)) %>%
  ungroup()

# Can also use tidyselect
df %>%
  group_by(where(is.character)) %>%
  summarize(mean_a = mean(a)) %>%
  ungroup()

Selection helper for grouping columns

Description

Selection helper for grouping columns

Usage

group_cols()

Examples

df <- tidytable(
  x = c("a", "b", "c"),
  y = 1:3,
  z = 1:3
)

df %>%
  group_by(x) %>%
  select(group_cols(), y)

Split data frame by groups

Description

Split data frame by groups. Returns a list.

Usage

group_split(.df, ..., .keep = TRUE, .named = FALSE)

Arguments

.df

A data.frame or data.table

...

Columns to group and split by. tidyselect compatible.

.keep

Should the grouping columns be kept

.named

experimental: Should the list be named with labels that identify the group

Examples

df <- tidytable(
  a = 1:3,
  b = 1:3,
  c = c("a", "a", "b"),
  d = c("a", "a", "b")
)

df %>%
  group_split(c, d)

df %>%
  group_split(c, d, .keep = FALSE)

df %>%
  group_split(c, d, .named = TRUE)

Get the grouping variables

Description

Get the grouping variables

Usage

group_vars(x)

Arguments

x

A grouped tidytable

Examples

df <- data.table(
  a = 1:3,
  b = 4:6,
  c = c("a", "a", "b"),
  d = c("a", "a", "b")
)

df %>%
  group_by(c, d) %>%
  group_vars()

Create conditions on a selection of columns

Description

Helpers to apply a filter across a selection of columns.

Usage

if_all(.cols = everything(), .fns = NULL, ...)

if_any(.cols = everything(), .fns = NULL, ...)

Arguments

.cols

Selection of columns

.fns

Function to create filter conditions

...

Other arguments passed to the function

Examples

iris %>%
  filter(if_any(ends_with("Width"), ~ .x > 4))

iris %>%
  filter(if_all(ends_with("Width"), ~ .x > 2))

Fast if_else

Description

Fast version of base::ifelse().

Usage

if_else(condition, true, false, missing = NA, ..., ptype = NULL, size = NULL)

Arguments

condition

Conditions to test on

true

Values to return if conditions evaluate to TRUE

false

Values to return if conditions evaluate to FALSE

missing

Value to return if an element of test is NA

...

These dots are for future extensions and must be empty.

ptype

Optional ptype to override output type

size

Optional size to override output size

Examples

x <- 1:5
if_else(x < 3, 1, 0)

# Can also be used inside of mutate()
df <- data.table(x = x)

df %>%
  mutate(new_col = if_else(x < 3, 1, 0))

Run invisible garbage collection

Description

Run garbage collection without the gc() output. Can also be run in the middle of a long pipe chain. Useful for large datasets or when using parallel processing.

Usage

inv_gc(x)

Arguments

x

Optional. If missing runs gc() silently. Else returns the same object unaltered.

Examples

# Can be run with no input
inv_gc()

df <- tidytable(col1 = 1, col2 = 2)

# Or can be used in the middle of a pipe chain (object is unaltered)
df %>%
  filter(col1 < 2, col2 < 4) %>%
  inv_gc() %>%
  select(col1)

Check if the tidytable is grouped

Description

Check if the tidytable is grouped

Usage

is_grouped_df(x)

Arguments

x

An object

Examples

df <- data.table(
  a = 1:3,
  b = c("a", "a", "b")
)

df %>%
  group_by(b) %>%
  is_grouped_df()

Test if the object is a tidytable

Description

This function returns TRUE for tidytables or subclasses of tidytables, and FALSE for all other objects.

Usage

is_tidytable(x)

Arguments

x

An object

Examples

df <- data.frame(x = 1:3, y = 1:3)

is_tidytable(df)

df <- tidytable(x = 1:3, y = 1:3)

is_tidytable(df)

Get lagging or leading values

Description

Find the "previous" or "next" values in a vector. Useful for comparing values behind or ahead of the current values.

Usage

lag(x, n = 1L, default = NA)

lead(x, n = 1L, default = NA)

Arguments

x

a vector of values

n

a positive integer of length 1, giving the number of positions to lead or lag by

default

value used for non-existent rows. Defaults to NA.

Examples

x <- 1:5

lag(x, 1)
lead(x, 1)

# Also works inside of `mutate()`
df <- tidytable(x = 1:5)

df %>%
  mutate(lag_x = lag(x))

Join two data.tables together

Description

Join two data.tables together

Usage

left_join(x, y, by = NULL, suffix = c(".x", ".y"), ..., keep = FALSE)

right_join(x, y, by = NULL, suffix = c(".x", ".y"), ..., keep = FALSE)

inner_join(x, y, by = NULL, suffix = c(".x", ".y"), ..., keep = FALSE)

full_join(x, y, by = NULL, suffix = c(".x", ".y"), ..., keep = FALSE)

anti_join(x, y, by = NULL)

semi_join(x, y, by = NULL)

Arguments

x

A data.frame or data.table

y

A data.frame or data.table

by

A character vector of variables to join by. If NULL, the default, the join will do a natural join, using all variables with common names across the two tables.

suffix

Append created for duplicated column names when using full_join()

...

Other parameters passed on to methods

keep

Should the join keys from both x and y be preserved in the output?

Examples

df1 <- data.table(x = c("a", "a", "b", "c"), y = 1:4)
df2 <- data.table(x = c("a", "b"), z = 5:6)

df1 %>% left_join(df2)
df1 %>% inner_join(df2)
df1 %>% right_join(df2)
df1 %>% full_join(df2)
df1 %>% anti_join(df2)

Apply a function to each element of a vector or list

Description

The map functions transform their input by applying a function to each element and returning a list/vector/data.table.

  • map() returns a list

  • ⁠_lgl()⁠, ⁠_int⁠, ⁠_dbl⁠,⁠_chr⁠, ⁠_df⁠ variants return their specified type

  • ⁠_dfr⁠ & ⁠_dfc⁠ Return all data frame results combined utilizing row or column binding

Usage

map(.x, .f, ...)

map_lgl(.x, .f, ...)

map_int(.x, .f, ...)

map_dbl(.x, .f, ...)

map_chr(.x, .f, ...)

map_dfc(.x, .f, ...)

map_dfr(.x, .f, ..., .id = NULL)

map_df(.x, .f, ..., .id = NULL)

walk(.x, .f, ...)

map_vec(.x, .f, ..., .ptype = NULL)

map2(.x, .y, .f, ...)

map2_lgl(.x, .y, .f, ...)

map2_int(.x, .y, .f, ...)

map2_dbl(.x, .y, .f, ...)

map2_chr(.x, .y, .f, ...)

map2_dfc(.x, .y, .f, ...)

map2_dfr(.x, .y, .f, ..., .id = NULL)

map2_df(.x, .y, .f, ..., .id = NULL)

map2_vec(.x, .y, .f, ..., .ptype = NULL)

pmap(.l, .f, ...)

pmap_lgl(.l, .f, ...)

pmap_int(.l, .f, ...)

pmap_dbl(.l, .f, ...)

pmap_chr(.l, .f, ...)

pmap_dfc(.l, .f, ...)

pmap_dfr(.l, .f, ..., .id = NULL)

pmap_df(.l, .f, ..., .id = NULL)

pmap_vec(.l, .f, ..., .ptype = NULL)

Arguments

.x

A list or vector

.f

A function

...

Other arguments to pass to a function

.id

Whether map_dfr() should add an id column to the finished dataset

.ptype

ptype for resulting vector in map_vec()

.y

A list or vector

.l

A list to use in pmap

Examples

map(c(1,2,3), ~ .x + 1)

map_dbl(c(1,2,3), ~ .x + 1)

map_chr(c(1,2,3), as.character)

Add/modify/delete columns

Description

With mutate() you can do 3 things:

  • Add new columns

  • Modify existing columns

  • Delete columns

Usage

mutate(
  .df,
  ...,
  .by = NULL,
  .keep = c("all", "used", "unused", "none"),
  .before = NULL,
  .after = NULL
)

Arguments

.df

A data.frame or data.table

...

Columns to add/modify

.by

Columns to group by

.keep

experimental: This is an experimental argument that allows you to control which columns from .df are retained in the output:

  • "all", the default, retains all variables.

  • "used" keeps any variables used to make new variables; it's useful for checking your work as it displays inputs and outputs side-by-side.

  • "unused" keeps only existing variables not used to make new variables.

  • "none", only keeps grouping keys (like transmute()).

.before, .after

Optionally indicate where new columns should be placed. Defaults to the right side of the data frame.

Examples

df <- data.table(
  a = 1:3,
  b = 4:6,
  c = c("a", "a", "b")
)

df %>%
  mutate(double_a = a * 2,
         a_plus_b = a + b)

df %>%
  mutate(double_a = a * 2,
         avg_a = mean(a),
         .by = c)

df %>%
  mutate(double_a = a * 2, .keep = "used")

df %>%
  mutate(double_a = a * 2, .after = a)

Add/modify columns by row

Description

Allows you to mutate "by row". this is most useful when a vectorized function doesn't exist.

Usage

mutate_rowwise(
  .df,
  ...,
  .keep = c("all", "used", "unused", "none"),
  .before = NULL,
  .after = NULL
)

Arguments

.df

A data.table or data.frame

...

Columns to add/modify

.keep

experimental: This is an experimental argument that allows you to control which columns from .df are retained in the output:

  • "all", the default, retains all variables.

  • "used" keeps any variables used to make new variables; it's useful for checking your work as it displays inputs and outputs side-by-side.

  • "unused" keeps only existing variables not used to make new variables.

  • "none", only keeps grouping keys (like transmute()).

.before, .after

Optionally indicate where new columns should be placed. Defaults to the right side of the data frame.

Examples

df <- data.table(x = 1:3, y = 1:3 * 2, z = 1:3 * 3)

# Compute the mean of x, y, z in each row
df %>%
  mutate_rowwise(row_mean = mean(c(x, y, z)))

# Use c_across() to more easily select many variables
df %>%
  mutate_rowwise(row_mean = mean(c_across(x:z)))

Number of observations in each group

Description

Helper function that can be used to find counts by group.

Can be used inside summarize(), mutate(), & filter()

Usage

n()

Examples

df <- data.table(
  x = 1:3,
  y = 4:6,
  z = c("a","a","b")
 )

df %>%
  summarize(count = n(), .by = z)

Count the number of unique values in a vector

Description

This is a faster version of length(unique(x)) that calls data.table::uniqueN().

Usage

n_distinct(..., na.rm = FALSE)

Arguments

...

vectors of values

na.rm

If TRUE missing values don't count

Examples

x <- sample(1:10, 1e5, rep = TRUE)
n_distinct(x)

Convert values to NA

Description

Convert values to NA.

Usage

na_if(x, y)

Arguments

x

A vector

y

Value to replace with NA

Examples

vec <- 1:3
na_if(vec, 3)

Nest columns into a list-column

Description

Nest columns into a list-column

Usage

nest(.df, ..., .by = NULL, .key = NULL, .names_sep = NULL)

Arguments

.df

A data.table or data.frame

...

Columns to be nested.

.by

Columns to nest by

.key

New column name if .by is used

.names_sep

If NULL, the names will be left alone. If a string, the names of the columns will be created by pasting together the inner column names and the outer column names.

Examples

df <- data.table(
  a = 1:3,
  b = 1:3,
  c = c("a", "a", "b"),
  d = c("a", "a", "b")
)

df %>%
  nest(data = c(a, b))

df %>%
  nest(data = where(is.numeric))

df %>%
  nest(.by = c(c, d))

Nest data.tables

Description

Nest data.tables by group.

Note: nest_by() does not return a rowwise tidytable.

Usage

nest_by(.df, ..., .key = "data", .keep = FALSE)

Arguments

.df

A data.frame or data.table

...

Columns to group by. If empty nests the entire data.table. tidyselect compatible.

.key

Name of the new column created by nesting.

.keep

Should the grouping columns be kept in the list column.

Examples

df <- data.table(
  a = 1:5,
  b = 6:10,
  c = c(rep("a", 3), rep("b", 2)),
  d = c(rep("a", 3), rep("b", 2))
)

df %>%
  nest_by()

df %>%
  nest_by(c, d)

df %>%
  nest_by(where(is.character))

df %>%
  nest_by(c, d, .keep = TRUE)

Nest join

Description

Join the data from y as a list column onto x.

Usage

nest_join(x, y, by = NULL, keep = FALSE, name = NULL, ...)

Arguments

x

A data.frame or data.table

y

A data.frame or data.table

by

A character vector of variables to join by. If NULL, the default, the join will do a natural join, using all variables with common names across the two tables.

keep

Should the join keys from both x and y be preserved in the output?

name

The name of the list-column created by the join. If NULL the name of y is used.

...

Other parameters passed on to methods

Examples

df1 <- tidytable(x = 1:3)
df2 <- tidytable(x = c(2, 3, 3), y = c("a", "b", "c"))

out <- nest_join(df1, df2)
out
out$df2

Create a tidytable from a list

Description

Create a tidytable from a list

Usage

new_tidytable(x = list())

Arguments

x

A named list of equal-length vectors. The lengths are not checked; it is the responsibility of the caller to make sure they are equal.

Examples

l <- list(x = 1:3, y = c("a", "a", "b"))

new_tidytable(l)

Selection version of across()

Description

Select a subset of columns from within functions like mutate(), summarize(), or filter().

Usage

pick(...)

Arguments

...

Columns to select. Tidyselect compatible.

Examples

df <- tidytable(
  x = 1:3,
  y = 4:6,
  z = c("a", "a", "b")
)

df %>%
  mutate(row_sum = rowSums(pick(x, y)))

Pivot data from wide to long

Description

pivot_longer() "lengthens" the data, increasing the number of rows and decreasing the number of columns.

Usage

pivot_longer(
  .df,
  cols = everything(),
  names_to = "name",
  values_to = "value",
  names_prefix = NULL,
  names_sep = NULL,
  names_pattern = NULL,
  names_ptypes = NULL,
  names_transform = NULL,
  names_repair = "check_unique",
  values_drop_na = FALSE,
  values_ptypes = NULL,
  values_transform = NULL,
  fast_pivot = FALSE,
  ...
)

Arguments

.df

A data.table or data.frame

cols

Columns to pivot. tidyselect compatible.

names_to

Name of the new "names" column. Must be a string.

values_to

Name of the new "values" column. Must be a string.

names_prefix

Remove matching text from the start of selected columns using regex.

names_sep

If names_to contains multiple values, names_sep takes the same specification as separate().

names_pattern

If names_to contains multiple values, names_pattern takes the same specification as extract(), a regular expression containing matching groups.

names_ptypes, values_ptypes

A list of column name-prototype pairs. See “?vctrs::'theory-faq-coercion“' for more info on vctrs coercion.

names_transform, values_transform

A list of column name-function pairs. Use these arguments if you need to change the types of specific columns.

names_repair

Treatment of duplicate names. See ?vctrs::vec_as_names for options/details.

values_drop_na

If TRUE, rows will be dropped that contain NAs.

fast_pivot

experimental: Fast pivoting. If TRUE, the names_to column will be returned as a factor, otherwise it will be a character column. Defaults to FALSE to match tidyverse semantics.

...

Additional arguments to passed on to methods.

Examples

df <- data.table(
  x = 1:3,
  y = 4:6,
  z = c("a", "b", "c")
)

df %>%
  pivot_longer(cols = c(x, y))

df %>%
  pivot_longer(cols = -z, names_to = "stuff", values_to = "things")

Pivot data from long to wide

Description

"Widens" data, increasing the number of columns and decreasing the number of rows.

Usage

pivot_wider(
  .df,
  names_from = name,
  values_from = value,
  id_cols = NULL,
  names_sep = "_",
  names_prefix = "",
  names_glue = NULL,
  names_sort = FALSE,
  names_repair = "unique",
  values_fill = NULL,
  values_fn = NULL,
  unused_fn = NULL
)

Arguments

.df

A data.frame or data.table

names_from

A pair of arguments describing which column (or columns) to get the name of the output column name_from, and which column (or columns) to get the cell values from values_from). tidyselect compatible.

values_from

A pair of arguments describing which column (or columns) to get the name of the output column name_from, and which column (or columns) to get the cell values from values_from. tidyselect compatible.

id_cols

A set of columns that uniquely identifies each observation. Defaults to all columns in the data table except for the columns specified in names_from and values_from. Typically used when you have additional variables that is directly related. tidyselect compatible.

names_sep

the separator between the names of the columns

names_prefix

prefix to add to the names of the new columns

names_glue

Instead of using names_sep and names_prefix, you can supply a glue specification that uses the names_from columns (and special .value) to create custom column names

names_sort

Should the resulting new columns be sorted.

names_repair

Treatment of duplicate names. See ?vctrs::vec_as_names for options/details.

values_fill

If values are missing, what value should be filled in

values_fn

Should the data be aggregated before casting? If the formula doesn't identify a single observation for each cell, then aggregation defaults to length with a message.

unused_fn

Aggregation function to be applied to unused columns. Default is to ignore unused columns.

Examples

df <- tidytable(
  id = 1,
  names = c("a", "b", "c"),
  vals = 1:3
)

df %>%
  pivot_wider(names_from = names, values_from = vals)

df %>%
  pivot_wider(
    names_from = names, values_from = vals, names_prefix = "new_"
  )

Pull out a single variable

Description

Pull a single variable from a data.table as a vector.

Usage

pull(.df, var = -1, name = NULL)

Arguments

.df

A data.frame or data.table

var

The column to pull from the data.table as:

  • a variable name

  • a positive integer giving the column position

  • a negative integer giving the column position counting from the right

name

Optional - specifies the column to be used as names for the vector.

Examples

df <- data.table(
  x = 1:3,
  y = 1:3
)

# Grab column by name
df %>%
  pull(y)

# Grab column by position
df %>%
  pull(1)

# Defaults to last column
df %>%
  pull()

Reframe a data frame

Description

Reframe a data frame. Note this is a simple alias for summarize() that always returns an ungrouped tidytable.

Usage

reframe(.df, ..., .by = NULL)

Arguments

.df

A data.frame or data.table

...

Aggregations to perform

.by

Columns to group by

Examples

mtcars %>%
  reframe(qs = quantile(disp, c(0.25, 0.75)),
          prob = c(0.25, 0.75),
          .by = cyl)

Relocate a column to a new position

Description

Move a column or columns to a new position

Usage

relocate(.df, ..., .before = NULL, .after = NULL)

Arguments

.df

A data.frame or data.table

...

A selection of columns to move. tidyselect compatible.

.before

Column to move selection before

.after

Column to move selection after

Examples

df <- data.table(
  a = 1:3,
  b = 1:3,
  c = c("a", "a", "b"),
  d = c("a", "a", "b")
)

df %>%
  relocate(c, .before = b)

df %>%
  relocate(a, b, .after = c)

df %>%
  relocate(where(is.numeric), .after = c)

Rename variables by name

Description

Rename variables from a data.table.

Usage

rename(.df, ...)

Arguments

.df

A data.frame or data.table

...

new_name = old_name pairs to rename columns

Examples

df <- data.table(x = 1:3, y = 4:6)

df %>%
  rename(new_x = x,
         new_y = y)

Rename multiple columns

Description

Rename multiple columns with the same transformation

Usage

rename_with(.df, .fn = NULL, .cols = everything(), ...)

Arguments

.df

A data.table or data.frame

.fn

Function to transform the names with.

.cols

Columns to rename. Defaults to all columns. tidyselect compatible.

...

Other parameters to pass to the function

Examples

df <- data.table(
  x = 1,
  y = 2,
  double_x = 2,
  double_y = 4
)

df %>%
  rename_with(toupper)

df %>%
  rename_with(~ toupper(.x))

df %>%
  rename_with(~ toupper(.x), .cols = c(x, double_x))

Replace missing values

Description

Replace NAs with specified values

Usage

replace_na(.x, replace)

Arguments

.x

A data.frame/data.table or a vector

replace

If .x is a data frame, a list() of replacement values for specified columns. If .x is a vector, a single replacement value.

Examples

df <- data.table(
  x = c(1, 2, NA),
  y = c(NA, 1, 2)
)

# Using replace_na() inside mutate()
df %>%
  mutate(x = replace_na(x, 5))

# Using replace_na() on a data frame
df %>%
  replace_na(list(x = 5, y = 0))

Ranking functions

Description

Ranking functions:

  • row_number(): Gives other row number if empty. Equivalent to frank(ties.method = "first") if provided a vector.

  • min_rank(): Equivalent to frank(ties.method = "min")

  • dense_rank(): Equivalent to frank(ties.method = "dense")

  • percent_rank(): Ranks by percentage from 0 to 1

  • cume_dist(): Cumulative distribution

Usage

row_number(x)

min_rank(x)

dense_rank(x)

percent_rank(x)

cume_dist(x)

Arguments

x

A vector to rank

Examples

df <- data.table(x = rep(1, 3), y = c("a", "a", "b"))

df %>%
  mutate(row = row_number())

Convert to a rowwise tidytable

Description

Convert to a rowwise tidytable.

Usage

rowwise(.df)

Arguments

.df

A data.frame or data.table

Examples

df <- tidytable(x = 1:3, y = 1:3 * 2, z = 1:3 * 3)

# Compute the mean of x, y, z in each row
df %>%
  rowwise() %>%
  mutate(row_mean = mean(c(x, y, z)))

# Use c_across() to more easily select many variables
df %>%
  rowwise() %>%
  mutate(row_mean = mean(c_across(x:z))) %>%
  ungroup()

Select or drop columns

Description

Select or drop columns from a data.table

Usage

select(.df, ...)

Arguments

.df

A data.frame or data.table

...

Columns to select or drop. Use named arguments, e.g. new_name = old_name, to rename selected variables. tidyselect compatible.

Examples

df <- data.table(
  x1 = 1:3,
  x2 = 1:3,
  y = c("a", "b", "c"),
  z = c("a", "b", "c")
)

df %>%
  select(x1, y)

df %>%
  select(x1:y)

df %>%
  select(-y, -z)

df %>%
  select(starts_with("x"), z)

df %>%
  select(where(is.character), x1)

df %>%
  select(new = x1, y)

Separate a character column into multiple columns

Description

Superseded

separate() has been superseded by separate_wider_delim().

Separates a single column into multiple columns using a user supplied separator or regex.

If a separator is not supplied one will be automatically detected.

Note: Using automatic detection or regex will be slower than simple separators such as "," or ".".

Usage

separate(
  .df,
  col,
  into,
  sep = "[^[:alnum:]]+",
  remove = TRUE,
  convert = FALSE,
  ...
)

Arguments

.df

A data frame

col

The column to split into multiple columns

into

New column names to split into. A character vector. Use NA to omit the variable in the output.

sep

Separator to split on. Can be specified or detected automatically

remove

If TRUE, remove the input column from the output data.table

convert

TRUE calls type.convert() with as.is = TRUE on new columns

...

Arguments passed on to methods

Examples

df <- data.table(x = c("a", "a.b", "a.b", NA))

# "sep" can be automatically detected (slower)
df %>%
  separate(x, into = c("c1", "c2"))

# Faster if "sep" is provided
df %>%
  separate(x, into = c("c1", "c2"), sep = ".")

Split a string into rows

Description

If a column contains observations with multiple delimited values, separate them each into their own row.

Usage

separate_longer_delim(.df, cols, delim, ...)

Arguments

.df

A data.frame or data.table

cols

Columns to separate

delim

Separator delimiting collapsed values

...

These dots are for future extensions and must be empty.

Examples

df <- data.table(
  x = 1:3,
  y = c("a", "d,e,f", "g,h"),
  z = c("1", "2,3,4", "5,6")
)

df %>%
  separate_longer_delim(c(y, z), ",")

Separate a collapsed column into multiple rows

Description

Superseded

separate_rows() has been superseded by separate_longer_delim().

If a column contains observations with multiple delimited values, separate them each into their own row.

Usage

separate_rows(.df, ..., sep = "[^[:alnum:].]+", convert = FALSE)

Arguments

.df

A data.frame or data.table

...

Columns to separate across multiple rows. tidyselect compatible

sep

Separator delimiting collapsed values

convert

If TRUE, runs type.convert() on the resulting column. Useful if the resulting column should be type integer/double.

Examples

df <- data.table(
  x = 1:3,
  y = c("a", "d,e,f", "g,h"),
  z = c("1", "2,3,4", "5,6")
)

separate_rows(df, y, z)

separate_rows(df, y, z, convert = TRUE)

Separate a character column into multiple columns

Description

Separates a single column into multiple columns

Usage

separate_wider_delim(
  .df,
  cols,
  delim,
  ...,
  names = NULL,
  names_sep = NULL,
  names_repair = "check_unique",
  too_few = c("align_start", "error"),
  too_many = c("drop", "error"),
  cols_remove = TRUE
)

Arguments

.df

A data frame

cols

Columns to separate

delim

Delimiter to separate on

...

These dots are for future extensions and must be empty.

names

New column names to separate into

names_sep

Names separator

names_repair

Treatment of duplicate names. See ?vctrs::vec_as_names for options/details.

too_few

What to do when too few column names are supplied

too_many

What to do when too many column names are supplied

cols_remove

Should old columns be removed

Examples

df <- tidytable(x = c("a", "a_b", "a_b", NA))

df %>%
  separate_wider_delim(x, delim = "_", names = c("left", "right"))

df %>%
  separate_wider_delim(x, delim = "_", names_sep = "")

Separate a character column into multiple columns using regex patterns

Description

Separate a character column into multiple columns using regex patterns

Usage

separate_wider_regex(
  .df,
  cols,
  patterns,
  ...,
  names_sep = NULL,
  names_repair = "check_unique",
  too_few = "error",
  cols_remove = TRUE
)

Arguments

.df

A data frame

cols

Columns to separate

patterns

patterns

...

These dots are for future extensions and must be empty.

names_sep

Names separator

names_repair

Treatment of duplicate names. See ?vctrs::vec_as_names for options/details.

too_few

What to do when too few column names are supplied

cols_remove

Should old columns be removed

Examples

df <- tidytable(id = 1:3, x = c("m-123", "f-455", "f-123"))

df %>%
  separate_wider_regex(x, c(gender = ".", ".", unit = "\\d+"))

Choose rows in a data.table

Description

Choose rows in a data.table. Grouped data.tables grab rows within each group.

Usage

slice_head(.df, n = 5, ..., .by = NULL, by = NULL)

slice_tail(.df, n = 5, ..., .by = NULL, by = NULL)

slice_max(.df, order_by, n = 1, ..., with_ties = TRUE, .by = NULL, by = NULL)

slice_min(.df, order_by, n = 1, ..., with_ties = TRUE, .by = NULL, by = NULL)

slice(.df, ..., .by = NULL)

slice_sample(
  .df,
  n,
  prop,
  weight_by = NULL,
  replace = FALSE,
  .by = NULL,
  by = NULL
)

Arguments

.df

A data.frame or data.table

n

Number of rows to grab

...

Integer row values

.by, by

Columns to group by

order_by

Variable to arrange by

with_ties

Should ties be kept together. The default TRUE may return can return multiple rows if they are equal. Use FALSE to ignore ties.

prop

The proportion of rows to select

weight_by

Sampling weights

replace

Should sampling be performed with (TRUE) or without (FALSE, default) replacement

Examples

df <- data.table(
  x = 1:4,
  y = 5:8,
  z = c("a", "a", "a", "b")
)

df %>%
  slice(1:3)

df %>%
  slice(1, 3)

df %>%
  slice(1:2, .by = z)

df %>%
  slice_head(1, .by = z)

df %>%
  slice_tail(1, .by = z)

df %>%
  slice_max(order_by = x, .by = z)

df %>%
  slice_min(order_by = y, .by = z)

Aggregate data using summary statistics

Description

Aggregate data using summary statistics such as mean or median. Can be calculated by group.

Usage

summarize(
  .df,
  ...,
  .by = NULL,
  .sort = TRUE,
  .groups = "drop_last",
  .unpack = FALSE
)

summarise(
  .df,
  ...,
  .by = NULL,
  .sort = TRUE,
  .groups = "drop_last",
  .unpack = FALSE
)

Arguments

.df

A data.frame or data.table

...

Aggregations to perform

.by

Columns to group by.

  • A single column can be passed with .by = d.

  • Multiple columns can be passed with .by = c(c, d)

  • tidyselect can be used:

    • Single predicate: .by = where(is.character)

    • Multiple predicates: .by = c(where(is.character), where(is.factor))

    • A combination of predicates and column names: .by = c(where(is.character), b)

.sort

experimental: Default TRUE. If FALSE the original order of the grouping variables will be preserved.

.groups

Grouping structure of the result

  • "drop_last": Drop the last level of grouping

  • "drop": Drop all groups

  • "keep": Keep all groups

.unpack

experimental: Default FALSE. Should unnamed data frame inputs be unpacked. The user must opt in to this option as it can lead to a reduction in performance.

Examples

df <- data.table(
  a = 1:3,
  b = 4:6,
  c = c("a", "a", "b"),
  d = c("a", "a", "b")
)

df %>%
  summarize(avg_a = mean(a),
            max_b = max(b),
            .by = c)

df %>%
  summarize(avg_a = mean(a),
            .by = c(c, d))

Build a data.table/tidytable

Description

Constructs a data.table, but one with nice printing features.

Usage

tidytable(..., .name_repair = "unique")

Arguments

...

A set of name-value pairs

.name_repair

Treatment of duplicate names. See ?vctrs::vec_as_names for options/details.

Examples

tidytable(x = 1:3, y = c("a", "a", "b"))

Select top (or bottom) n rows (by value)

Description

Select the top or bottom entries in each group, ordered by wt.

Usage

top_n(.df, n = 5, wt = NULL, .by = NULL)

Arguments

.df

A data.frame or data.table

n

Number of rows to return

wt

Optional. The variable to use for ordering. If NULL uses the last column in the data.table.

.by

Columns to group by

Examples

df <- data.table(
  x = 1:5,
  y = 6:10,
  z = c(rep("a", 3), rep("b", 2))
)

df %>%
  top_n(2, wt = y)

df %>%
  top_n(2, wt = y, .by = z)

Add new variables and drop all others

Description

Unlike mutate(), transmute() keeps only the variables that you create

Usage

transmute(.df, ..., .by = NULL)

Arguments

.df

A data.frame or data.table

...

Columns to create/modify

.by

Columns to group by

Examples

df <- data.table(
  a = 1:3,
  b = 4:6,
  c = c("a", "a", "b")
)

df %>%
  transmute(double_a = a * 2)

Rowwise tidytable creation

Description

Create a tidytable using a rowwise setup.

Usage

tribble(...)

Arguments

...

Column names as formulas, values below. See example.

Examples

tribble(
  ~ x, ~ y,
  "a", 1,
  "b", 2,
  "c", 3
)

Uncount a data.table

Description

Uncount a data.table

Usage

uncount(.df, weights, .remove = TRUE, .id = NULL)

Arguments

.df

A data.frame or data.table

weights

A column containing the weights to uncount by

.remove

If TRUE removes the selected weights column

.id

A string name for a new column containing a unique identifier for the newly uncounted rows.

Examples

df <- data.table(x = c("a", "b"), n = c(1, 2))

uncount(df, n)

uncount(df, n, .id = "id")

Unite multiple columns by pasting strings together

Description

Convenience function to paste together multiple columns into one.

Usage

unite(.df, col = ".united", ..., sep = "_", remove = TRUE, na.rm = FALSE)

Arguments

.df

A data.frame or data.table

col

Name of the new column, as a string.

...

Selection of columns. If empty all variables are selected. tidyselect compatible.

sep

Separator to use between values

remove

If TRUE, removes input columns from the data.table.

na.rm

If TRUE, NA values will be not be part of the concatenation

Examples

df <- tidytable(
    a = c("a", "a", "a"),
    b = c("b", "b", "b"),
    c = c("c", "c", NA)
)

df %>%
  unite("new_col", b, c)

df %>%
  unite("new_col", where(is.character))

df %>%
  unite("new_col", b, c, remove = FALSE)

df %>%
  unite("new_col", b, c, na.rm = TRUE)

df %>%
  unite()

Unnest list-columns

Description

Unnest list-columns.

Usage

unnest(
  .df,
  ...,
  keep_empty = FALSE,
  .drop = TRUE,
  names_sep = NULL,
  names_repair = "unique"
)

Arguments

.df

A data.table

...

Columns to unnest If empty, unnests all list columns. tidyselect compatible.

keep_empty

Return NA for any NULL elements of the list column

.drop

Should list columns that were not unnested be dropped

names_sep

If NULL, the default, the inner column names will become the new outer column names.

If a string, the name of the outer column will be appended to the beginning of the inner column names, with names_sep used as a separator.

names_repair

Treatment of duplicate names. See ?vctrs::vec_as_names for options/details.

Examples

df1 <- tidytable(x = 1:3, y = 1:3)
df2 <- tidytable(x = 1:2, y = 1:2)
nested_df <-
  data.table(
    a = c("a", "b"),
    frame_list = list(df1, df2),
    vec_list = list(4:6, 7:8)
  )

nested_df %>%
  unnest(frame_list)

nested_df %>%
  unnest(frame_list, names_sep = "_")

nested_df %>%
  unnest(frame_list, vec_list)

Unnest a list-column of vectors into regular columns

Description

Turns each element of a list-column into a row.

Usage

unnest_longer(
  .df,
  col,
  values_to = NULL,
  indices_to = NULL,
  indices_include = NULL,
  keep_empty = FALSE,
  names_repair = "check_unique",
  simplify = NULL,
  ptype = NULL,
  transform = NULL
)

Arguments

.df

A data.table or data.frame

col

Column to unnest

values_to

Name of column to store values

indices_to

Name of column to store indices

indices_include

Should an index column be included? Defaults to TRUE when col has inner names.

keep_empty

Return NA for any NULL elements of the list column

names_repair

Treatment of duplicate names. See ?vctrs::vec_as_names for options/details.

simplify

Currently not supported. Errors if not NULL.

ptype

Optionally a named list of ptypes declaring the desired output type of each component.

transform

Optionally a named list of transformation functions applied to each component.

Examples

df <- tidytable(
  x = 1:3,
  y = list(0, 1:3, 4:5)
)

df %>% unnest_longer(y)

Unnest a list-column of vectors into a wide data frame

Description

Unnest a list-column of vectors into a wide data frame

Usage

unnest_wider(
  .df,
  col,
  names_sep = NULL,
  simplify = NULL,
  names_repair = "check_unique",
  ptype = NULL,
  transform = NULL
)

Arguments

.df

A data.table or data.frame

col

Column to unnest

names_sep

If NULL, the default, the names will be left as they are. If a string, the inner and outer names will be pasted together with names_sep as the separator.

simplify

Currently not supported. Errors if not NULL.

names_repair

Treatment of duplicate names. See ?vctrs::vec_as_names for options/details.

ptype

Optionally a named list of ptypes declaring the desired output type of each component.

transform

Optionally a named list of transformation functions applied to each component.

Examples

df <- tidytable(
  x = 1:3,
  y = list(0, 1:3, 4:5)
)

# Automatically creates names
df %>% unnest_wider(y)

# But you can provide names_sep for increased naming control
df %>% unnest_wider(y, names_sep = "_")