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This function is comparable to dplyr::group_by(), but just following the datawizard function design. data_ungroup() removes the grouping information from a grouped data frame.

Usage

data_group(
  x,
  select = NULL,
  exclude = NULL,
  ignore_case = FALSE,
  verbose = TRUE,
  ...
)

data_ungroup(x, verbose = TRUE, ...)

Arguments

x

A data frame

select

Variables that will be included when performing the required tasks. Can be either

  • a variable specified as a literal variable name (e.g., column_name),

  • a string with the variable name (e.g., "column_name"), or a character vector of variable names (e.g., c("col1", "col2", "col3")),

  • a formula with variable names (e.g., ~column_1 + column_2),

  • a vector of positive integers, giving the positions counting from the left (e.g. 1 or c(1, 3, 5)),

  • a vector of negative integers, giving the positions counting from the right (e.g., -1 or -1:-3),

  • one of the following select-helpers: starts_with(""), ends_with(""), contains(""), a range using : or regex(""),

  • or a function testing for logical conditions, e.g. is.numeric() (or is.numeric), or any user-defined function that selects the variables for which the function returns TRUE (like: foo <- function(x) mean(x) > 3),

  • ranges specified via literal variable names, select-helpers (except regex()) and (user-defined) functions can be negated, i.e. return non-matching elements, when prefixed with a -, e.g. -ends_with(""), -is.numeric or -Sepal.Width:Petal.Length. Note: Negation means that matches are excluded, and thus, the exclude argument can be used alternatively. For instance, select=-ends_with("Length") (with -) is equivalent to exclude=ends_with("Length") (no -). In case negation should not work as expected, use the exclude argument instead.

If NULL, selects all columns. Patterns that found no matches are silently ignored, e.g. find_columns(iris, select = c("Species", "Test")) will just return "Species".

exclude

See select, however, column names matched by the pattern from exclude will be excluded instead of selected. If NULL (the default), excludes no columns.

ignore_case

Logical, if TRUE and when one of the select-helpers or a regular expression is used in select, ignores lower/upper case in the search pattern when matching against variable names.

verbose

Toggle warnings.

...

Arguments passed down to other functions. Mostly not used yet.

Value

A grouped data frame, i.e. a data frame with additional information about the grouping structure saved as attributes.

Examples

data(efc)
if (requireNamespace("poorman")) {
  suppressPackageStartupMessages(library(poorman, quietly = TRUE))

  # total mean
  efc %>%
    summarize(mean_hours = mean(c12hour, na.rm = TRUE))

  # mean by educational level
  efc %>%
    data_group(c172code) %>%
    summarize(mean_hours = mean(c12hour, na.rm = TRUE))
}
#> Loading required namespace: poorman
#> # A tibble: 3 × 2
#> # Groups:   c172code [3]
#>   c172code mean_hours
#>      <dbl>      <dbl>
#> 1        1       87.1
#> 2        2       94.0
#> 3        3       75