Create a tplyr_layer object

This object is the workhorse of the tplyr package. A tplyr_layer can be thought of as a block, or "layer" of a table. Summary tables typically consist of different sections that require different summaries. When programming these section, your code will create different layers that need to be stacked or merged together. A tplyr_layer is the container for those isolated building blocks.

When building the tplyr_table, each layer will execute independently. When all of the data processing has completed, the layers are brought together to construct the output.

tplyr_layer objects are not created directly, but are rather created using the layer constructor functions group_count, group_desc, and group_shift.

Usage

tplyr_layer(parent, target_var, by, where, type, ...)

Arguments

parent

tplyr_table or tplyr_layer. Required. The parent environment of the layer. This must be either the tplyr_table object that the layer is contained within, or another tplyr_layer object of which the layer is a subgroup.

target_var

Symbol. Required, The variable name on which the summary is to be performed. Must be a variable within the target dataset. Enter unquoted - i.e. target_var = AEBODSYS.

by

A string, a variable name, or a list of variable names supplied using dplyr::vars

where

Call. Filter logic used to subset the target data when performing a summary.

type

"count", "desc", or "shift". Required. The category of layer - either "counts" for categorical counts, "desc" for descriptive statistics, or "shift" for shift table counts

...

Additional arguments

Value

A tplyr_layer environment that is a child of the specified parent. The environment contains the object as listed below.

tplyr_layer Core Object Structure

type

This is an attribute. A string indicating the layer type, which controls the summary that will be performed.

target_var

A quosure of a name, which is the variable on which a summary will be performed.

by

A list of quosures representing either text labels or variable names used in grouping. Variable names must exist within the target dataset Text strings submitted do not need to exist in the target dataset.

cols

A list of quosures used to determine the variables that are used to display in columns.

where

A quosure of a call that containers the filter logic used to subset the target dataset. This filtering is in addition to any subsetting done based on where criteria specified in tplyr_table

layers

A list with class tplyr_layer_container. Initialized as empty, but serves as the container for any sublayers of the current layer. Used internally.

Different layer types will have some different bindings specific to that layer's needs.

See also

tplyr_table

Examples

tab <- tplyr_table(iris, Sepal.Width)

l <- group_count(tab, by=vars('Label Text', Species),
                 target_var=Species, where= Sepal.Width < 5.5,
                 cols = Species)