get_meta_result: Extract the result metadata of a Tplyr table

In Tplyr: A Traceability Focused Grammar of Clinical Data Summary

Extract the result metadata of a Tplyr table

Description

Given a row_id value and a result column, this function will return the tplyr_meta object associated with that 'cell'.

Usage

get_meta_result(x, row_id, column, ...)

Arguments

x	A built Tplyr table or a dataframe
row_id	The row_id value of the desired cell, provided as a character string
column	The result column of interest, provided as a character string
...	additional arguments

Details

If a Tplyr table is built with the metadata=TRUE option specified, then metadata is assembled behind the scenes to provide traceability on each result cell derived. The functions get_meta_result() and get_meta_subset() allow you to access that metadata by using an ID provided in the row_id column and the column name of the result you'd like to access. The purpose is of the row_id variable instead of a simple row index is to provide a sort resistant reference of the originating column, so the output Tplyr table can be sorted in any order but the metadata are still easily accessible.

The tplyr_meta object provided a list with two elements - names and filters. The metadata contain every column from the target data.frame of the Tplyr table that factored into the specified result cell, and the filters contains all the necessary filters to subset to data summarized to create the specified result cell. get_meta_subset() additionally provides a parameter to specify any additional columns you would like to include in the returned subset data frame.

Value

A tplyr_meta object

Examples

t <- tplyr_table(mtcars, cyl) %>%
  add_layer(
    group_desc(hp)
  )

dat <- t %>% build(metadata = TRUE)

get_meta_result(t, 'd1_1', 'var1_4')

m <- t$metadata
dat <- t$target

get_meta_result(t, 'd1_1', 'var1_4')

Tplyr documentation built on May 29, 2024, 10:37 a.m.