expandColumn: Expand a column of vectors into one row per value of each...

In WinVector/replyr: Patches to Use 'dplyr' on Remote Data Sources

Description

Similar to tidyr::unnest but lands rowids and value ids, and can work on remote data sources. Fairly expensive per-row operation, not suitable for big data.

Usage

expandColumn(
  data,
  colName,
  ...,
  rowidSource = NULL,
  rowidDest = NULL,
  idxDest = NULL,
  tempNameGenerator = mk_tmp_name_source("replyr_expandColumn")
)

Arguments

data	data.frame to work with.
colName	character name of column to expand.
...	force later arguments to be bound by name
rowidSource	optional character name of column to take row indices from (rowidDest must be NULL to use this).
rowidDest	optional character name of column to write row indices to (must not be an existing column name, rowidSource must be NULL to use this).
idxDest	optional character name of column to write value indices to (must not be an existing column name).
tempNameGenerator	temp name generator produced by wrapr::mk_tmp_name_source, used to record dplyr::compute() effects.

Value

expanded data frame where each value of colName column is in a new row.

Examples

d <- data.frame(name= c('a','b'))
d$value <- list(c('x','y'),'z')
expandColumn(d, 'value',
             rowidDest= 'origRowId',
             idxDest= 'valueIndex')

WinVector/replyr documentation built on Oct. 22, 2020, 8:07 p.m.