ljoinf {easyr}

Left Join with Factors

Description

Matches factor levels before left join via merge. Author: Bryce Chamberlain.

Usage

ljoinf(
  data.left,
  data.right,
  by,
  sort.levels = TRUE,
  restrict.levels = FALSE,
  na_level = "(Missing)"
)

Arguments

data.left

Left data. All of this data will be preservered in the join (may still result in duplication).

data.right

Right data. Only rows that matche the join will be included (may also result in duplication).

by

Columns to join on.

sort.levels

Sort the factor levels after combining them.

restrict.levels

Often the joined data won't use all the levels in both datasets. Set to TRUE to remove factor levels that aren't in the joined data.

na_level

some functions don't like factors to have NAs so we replace NAs with this value for factors only. Set NULL to skip.

Value

Joined data, with any factors modified to contain all levels in the joined data.

Examples

df1 = data.frame(
  factor1 = c( 'a', 'b', 'c' ),
  factor2 = c( 'high', 'medium', 'low' ),
  factor.join = c( '0349038u093843', '304359867893753', '3409783509735' ),
  numeric = c( 1, 2, 3 ),
  logical = c( TRUE, TRUE, TRUE )
)

df2 = data.frame(
  factor1 = c( 'd', 'e', 'f' ),
  factor2 = c( 'low', 'medium', 'high' ),
  factor.join = c( '32532532536', '304359867893753', '32534745876' ),
  numeric = c( 4, 5, 6 ),
  logical = c( FALSE, FALSE, FALSE )
)

ljoinf( df1, df2, by = 'factor.join' )