select_sample: Randomly select samples from a sampling frame with or without...
In tereom/mapacurracy: Computing map accuracies

Description Usage Arguments Value Examples

Given a data.frame with sample size allocation per strata and a data.frame with the sampling frame it selects random samples.

1 2	select_sample(allocation, sampling_frame, sample_size = sample_size, stratum = stratum)

`allocation`	`data.frame` with a column defining the strata and a column with sample size allocations for each stratum (one line per stratum).
`sampling_frame`	`data.frame` with the sampling frame it must contain a column with the stratum.
`sample_size`	unquoted column with sample sizes in the allocation data.frame
`stratum`	unquoted column with strata in the allocation and sampling_frame `data.frame`'s (the columns must have the same name in the two `data.frame`'s)

A data.frame with the selected sample, it will have the same columns as the original sampling frame plus a column indicating the sample size in the stratum of each selected observation.

sampling_frame <- data.frame(id = 1:100,
  str = sample(1:5, 100, replace = TRUE),
  val = rnorm(100))
allo <- sampling_frame %>%
    group_by(str) %>%
    summarise(n = 0.4 * n())
select_sample(allo, sampling_frame, n, str)