Choose rows in a data.table
Choose rows in a data.table. Grouped data.tables grab rows within each group.
slice.(.df, ..., .by = NULL) slice_head.(.df, n = 5, .by = NULL) slice_tail.(.df, n = 5, .by = NULL) slice_max.(.df, order_by, n = 1, .by = NULL) slice_min.(.df, order_by, n = 1, .by = NULL) slice_sample.(.df, n, prop, weight_by = NULL, replace = FALSE, .by = NULL)
.df |
A data.frame or data.table |
... |
Integer row values |
.by |
Columns to group by |
n |
Number of rows to grab |
order_by |
Variable to arrange by |
prop |
The proportion of rows to select |
weight_by |
Sampling weights |
replace |
Should sampling be performed with ( |
test_df <- data.table(
x = 1:4,
y = 5:8,
z = c("a","a","a","b")
)
test_df %>%
slice.(1:3)
test_df %>%
slice.(1, 3)
test_df %>%
slice.(1:2, .by = z)
test_df %>%
slice_head.(1, .by = z)
test_df %>%
slice_tail.(1, .by = z)
test_df %>%
slice_max.(order_by = x, .by = z)
test_df %>%
slice_min.(order_by = y, .by = z)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.