ir (version 0.4.1)

nest: Nest and un-nest an ir object

Description

Nest and un-nest an ir object

Usage

nest.ir(.data, ..., .names_sep = NULL, .key = deprecated())
unnest.ir(
  data,
  cols,
  ...,
  keep_empty = FALSE,
  ptype = NULL,
  names_sep = NULL,
  names_repair = "check_unique",
  .drop = deprecated(),
  .id = deprecated(),
  .sep = deprecated(),
  .preserve = deprecated()
)

Value

.data with nested or unnested columns. If the spectra column is dropped or invalidated (see ir_new_ir()), the ir class is dropped, else the object is of class ir.

Arguments

.data

An object of class ir.

...

<tidy-select> Columns to nest; these will appear in the inner data frames.

Specified using name-variable pairs of the form new_col = c(col1, col2, col3). The right hand side can be any valid tidyselect expression.

If not supplied, then ... is derived as all columns not selected by .by, and will use the column name from .key.

: previously you could write df %>% nest(x, y, z). Convert to df %>% nest(data = c(x, y, z)).

.key

The name of the resulting nested column. Only applicable when ... isn't specified, i.e. in the case of df %>% nest(.by = x).

If NULL, then "data" will be used by default.

data

A data frame.

cols

<tidy-select> List-columns to unnest.

When selecting multiple columns, values from the same row will be recycled to their common size.

keep_empty

By default, you get one row of output for each element of the list that you are unchopping/unnesting. This means that if there's a size-0 element (like NULL or an empty data frame or vector), then that entire row will be dropped from the output. If you want to preserve all rows, use keep_empty = TRUE to replace size-0 elements with a single row of missing values.

ptype

Optionally, a named list of column name-prototype pairs to coerce cols to, overriding the default that will be guessed from combining the individual values. Alternatively, a single empty ptype can be supplied, which will be applied to all cols.

names_sep, .names_sep

If NULL, the default, the names will be left as is. In nest(), inner names will come from the former outer names; in unnest(), the new outer names will come from the inner names.

If a string, the inner and outer names will be used together. In unnest(), the names of the new outer columns will be formed by pasting together the outer and the inner column names, separated by names_sep. In nest(), the new inner names will have the outer names + names_sep automatically stripped. This makes names_sep roughly symmetric between nesting and unnesting.

names_repair

Used to check that output data frame has valid names. Must be one of the following options:

• "minimal": no name repair or checks, beyond basic existence,

• "unique": make sure names are unique and not empty,

• "check_unique": (the default), no name repair, but check they are unique,

• "universal": make the names unique and syntactic

• a function: apply custom name repair.

• tidyr_legacy: use the name repair from tidyr 0.8.

• a formula: a purrr-style anonymous function (see rlang::as_function())

See vctrs::vec_as_names() for more details on these terms and the strategies used to enforce them.

.drop, .preserve

: all list-columns are now preserved; If there are any that you don't want in the output use select() to remove them prior to unnesting.

.id

: convert df %>% unnest(x, .id = "id") to df %>% mutate(id = names(x)) %>% unnest(x)).

.sep

: use names_sep instead.

See Also

Other tidyverse: arrange.ir(), distinct.ir(), extract.ir(), filter-joins, filter.ir(), group_by, mutate, mutate-joins, pivot_longer.ir(), pivot_wider.ir(), rename, rowwise.ir(), select.ir(), separate.ir(), separate_rows.ir(), slice, summarize, unite.ir()

Examples

## nest
ir_sample_data |>
  tidyr::nest(
    contents = c(holocellulose, klason_lignin)
  )


## unnest
ir_sample_data |>
  tidyr::nest(
    contents = c(holocellulose, klason_lignin)
  ) |>
  tidyr::unnest("contents")