sample: Sample rows randomly from a table

In tidyfst: Tidy Verbs for Fast Data Manipulation

Sample rows randomly from a table

Description

Select a number or proportion of rows randomly from the data frame

sample_dt is a merged version of sample_n_dt and sample_frac_dt, this could be convenient.

Usage

sample_dt(.data, n = NULL, prop = NULL, replace = FALSE, by = NULL)

sample_n_dt(.data, size, replace = FALSE, by = NULL)

sample_frac_dt(.data, size, replace = FALSE, by = NULL)

Arguments

.data	A data.frame
n	Number of rows to select
prop	Fraction of rows to select
replace	Sample with or without replacement? Default uses FALSE.
by	(Optional) Character. Specify if you want to sample by group.
size	For sample_n_dt, the number of rows to select. For sample_frac_dt, the fraction of rows to select.

Value

data.table

See Also

sample_n,sample_frac

Examples

sample_n_dt(mtcars, 10)
sample_n_dt(mtcars, 50, replace = TRUE)
sample_frac_dt(mtcars, 0.1)
sample_frac_dt(mtcars, 1.5, replace = TRUE)


sample_dt(mtcars,n=10)
sample_dt(mtcars,prop = 0.1)


# sample by group(s)
iris %>% sample_n_dt(2,by = "Species")
iris %>% sample_frac_dt(.1,by = "Species")

mtcars %>% sample_n_dt(1,by = "cyl,vs")
# equals to
mtcars %>% sample_n_dt(1,by = c("cyl","vs"))

tidyfst documentation built on July 26, 2023, 5:20 p.m.