Pivot Longer block constructor

This block reshapes data from wide to long format by pivoting multiple columns into two columns: one containing the original column names and another containing the values (see tidyr::pivot_longer()).

Usage

new_pivot_longer_block(
  cols = character(),
  names_to = "name",
  values_to = "value",
  values_drop_na = FALSE,
  names_prefix = "",
  ...
)

Arguments

cols

Character vector of column names to pivot into longer format. If empty, all columns will be available for selection.

names_to

Name of the new column to create from the column names. Default is "name".

values_to

Name of the new column to create from the values. Default is "value".

values_drop_na

If TRUE, rows with NA values will be dropped. Default is FALSE.

names_prefix

Optional prefix to remove from column names before storing in the names_to column. For example, "col_" would remove that prefix from column names like "col_a", "col_b".

...

Additional arguments forwarded to blockr.core::new_transform_block()

Value

A block object for pivot_longer operations

See also

blockr.core::new_transform_block(), tidyr::pivot_longer()

Examples

# Create a pivot longer block
new_pivot_longer_block()
#> <pivot_longer_block<transform_block<block>>>
#> Name: "Pivot longer"
#> Data inputs: "data"
#> Initial block state:
#>  $ cols          : chr(0)
#>  $ names_to      : chr "name"
#>  $ values_to     : chr "value"
#>  $ values_drop_na: logi FALSE
#>  $ names_prefix  : chr ""
#> Constructor: blockr.dplyr::new_pivot_longer_block()

if (interactive()) {
  # Basic usage with wide format data
  library(blockr.core)
  wide_data <- data.frame(
    id = 1:3,
    measurement_a = c(10, 20, 30),
    measurement_b = c(15, 25, 35),
    measurement_c = c(12, 22, 32)
  )
  serve(
    new_pivot_longer_block(
      cols = c("measurement_a", "measurement_b", "measurement_c"),
      names_to = "measurement_type",
      values_to = "value"
    ),
    data = list(data = wide_data)
  )

  # With names_prefix to clean column names
  serve(
    new_pivot_longer_block(
      cols = c("measurement_a", "measurement_b", "measurement_c"),
      names_to = "type",
      values_to = "measurement",
      names_prefix = "measurement_"
    ),
    data = list(data = wide_data)
  )
}