Add/modify/delete columns
With mutate.() you can do 3 things:
Add new columns
Modify existing columns
Delete columns
mutate.(.df, ..., .by = NULL)
.df |
A data.frame or data.table |
... |
Columns to add/modify |
.by |
Columns to group by |
test_df <- data.table(
a = c(1,2,3),
b = c(4,5,6),
c = c("a","a","b")
)
test_df %>%
mutate.(double_a = a * 2,
a_plus_b = a + b)
test_df %>%
mutate.(double_a = a * 2,
avg_a = mean(a),
.by = c)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.