kim (version 0.5.3)

merge_data_tables: Merge data tables

Description

Merge two data.table objects. If there are any duplicated ID values and column names across the two data tables, the cell values in the first data.table will remain intact and the cell values in the second data.table will be discarded for the resulting merged data table.

Usage

merge_data_tables(dt1 = NULL, dt2 = NULL, id = NULL, silent = TRUE)

Value

a data.table object, which merges (joins) the second data.table around the first data.table.

Arguments

dt1

the first data.table which will remain intact

dt2

the second data.table which will be joined outside of (around) the first data.table. If there are any duplicated ID values and column names across the two data tables, the cell values in the first data.table will remain intact and the cell values in the second data.table will be discarded for the resulting merged data table.

id

name of the column that will contain the ID values in the two data tables. The name of the ID column must be identical in the two data tables.

silent

If silent = TRUE, no message will be printed regarding how many ID values and column names were duplicated. If silent = FALSE, messages will be printed regarding how many ID values and column names were duplicated. (default = FALSE)

Examples

data_1 <- data.table::data.table(
id_col = c(4, 2, 1, 3),
a = 3:6,
b = 5:8,
c = c("w", "x", "y", "z"))
data_2 <- data.table::data.table(
id_col = c(1, 99, 4),
e = 6:8,
b = c("p", "q", "r"),
d = c(TRUE, FALSE, FALSE))
merge_data_tables(dt1 = data_1, dt2 = data_2, id = "id_col")
data_3 <- data.table::data.table(
id_col = 99,
a = "abc",
b = TRUE,
c = TRUE)
# Note how the value of TRUE gets converted to 1 when merging in Column 'c'
merge_data_tables(data_1, data_3, id = "id_col")
data_4 <- data.table::data.table(
id_col = c(5, 3),
a = c("a", NA))
data_5 <- data.table::data.table(
id_col = 1,
a = 2)
merge_data_tables(data_4, data_5, id = "id_col")