mintyr (version 0.1.0)

w2l_nest: Reshape Wide Data to Long Format and Nest by Specified Columns

Description

The w2l_nest function reshapes wide-format data into long-format and nests it by specified columns. It handles both data.frame and data.table objects and provides options for grouping and nesting the data.

Usage

w2l_nest(data, cols2l = NULL, by = NULL, nest_type = "dt")

Value

data.table with nested data in long format, grouped by specified columns if provided. Each row contains a nested data.table or data.frame under the column data, depending on nest_type.

• If by is NULL, returns a data.table nested by name.

• If by is specified, returns a data.table nested by name and the grouping variables.

Arguments

data

data.frame or data.table

• Input dataset in wide format

• Automatically converted to data.table if necessary

cols2l

numeric or character columns to transform

• Specifies columns for wide-to-long conversion

• Can be column indices or column names

• Default is NULL

by

numeric or character grouping variables

• Optional columns for additional data stratification

• Can be column indices or column names

• Used to create hierarchical nested structures

• Default is NULL

nest_type

character output data type

• Defines nested data object type

• Possible values:

  • "dt": nested data.table

  • "df": nested data.frame

• Default is "dt"

Details

The function melts the specified wide columns into long format and nests the resulting data by the name column and any additional grouping variables specified in by. The nested data can be in the form of data.table or data.frame objects, controlled by the nest_type parameter.

Both cols2l and by parameters accept either column indices or column names, providing flexible ways to specify the columns for transformation and grouping.

See Also

Related functions and packages:

• tidytable::nest_by() Nest data.tables by group

Examples

# Example: Wide to long format nesting demonstrations

# Example 1: Basic nesting by group
w2l_nest(
  data = iris,                    # Input dataset
  by = "Species"                  # Group by Species column
)

# Example 2: Nest specific columns with numeric indices
w2l_nest(
  data = iris,                    # Input dataset
  cols2l = 1:4,                   # Select first 4 columns to nest
  by = "Species"                  # Group by Species column
)

# Example 3: Nest specific columns with column names
w2l_nest(
  data = iris,                    # Input dataset
  cols2l = c("Sepal.Length",      # Select columns by name
             "Sepal.Width", 
             "Petal.Length"),
  by = 5                          # Group by column index 5 (Species)
)
# Returns similar structure to Example 2