JoinTables: Inner, Left, Right, Outer, Semi and Anti Join for Data Tables

In mllg/batchtools: Tools for Computation on Batch Systems

Inner, Left, Right, Outer, Semi and Anti Join for Data Tables

Description

These helper functions perform join operations on data tables. Most of them are basically one-liners. See https://rpubs.com/ronasta/join_data_tables for a overview of join operations in data table or alternatively dplyr's vignette on two table verbs.

Usage

ijoin(x, y, by = NULL)

ljoin(x, y, by = NULL)

rjoin(x, y, by = NULL)

ojoin(x, y, by = NULL)

sjoin(x, y, by = NULL)

ajoin(x, y, by = NULL)

ujoin(x, y, all.y = FALSE, by = NULL)

Arguments

x	[data.frame] First data.frame to join.
y	[data.frame] Second data.frame to join.
by	[character] Column name(s) of variables used to match rows in x and y. If not provided, a heuristic similar to the one described in the dplyr vignette is used: If x is keyed, the existing key will be used if y has the same column(s). If x is not keyed, the intersect of common columns names is used if not empty. Raise an exception. You may pass a named character vector to merge on columns with different names in x and y: by = c("x.id" = "y.id") will match x's “x.id” column with y\'s “y.id” column.
all.y	[logical(1)] Keep columns of y which are not in x?

Value

[data.table] with key identical to by.

Examples

# Create two tables for demonstration
tmp = makeRegistry(file.dir = NA, make.default = FALSE)
batchMap(identity, x = 1:6, reg = tmp)
x = getJobPars(reg = tmp)
y = findJobs(x >= 2 & x <= 5, reg = tmp)
y$extra.col = head(letters, nrow(y))

# Inner join: similar to intersect(): keep all columns of x and y with common matches
ijoin(x, y)

# Left join: use all ids from x, keep all columns of x and y
ljoin(x, y)

# Right join: use all ids from y, keep all columns of x and y
rjoin(x, y)

# Outer join: similar to union(): keep all columns of x and y with matches in x or y
ojoin(x, y)

# Semi join: filter x with matches in y
sjoin(x, y)

# Anti join: filter x with matches not in y
ajoin(x, y)

# Updating join: Replace values in x with values in y
ujoin(x, y)

mllg/batchtools documentation built on April 21, 2023, 11:49 a.m.