R: Obtain inclusion probabilities

obtain_inclusion_probabilities {randomizr} | R Documentation

## Obtain inclusion probabilities

### Description

You can either give obtain_inclusion_probabilities() an declaration, as created by `declare_rs` or you can specify the other arguments to describe a random sampling procedure.
This function is especially useful when units have different inclusion probabilities and the analyst plans to use inverse-probability weights.

### Usage

    obtain_inclusion_probabilities(declaration = NULL, N = NULL,
      strata = NULL, clusters = NULL, n = NULL, prob = NULL,
      strata_n = NULL, strata_prob = NULL, simple = FALSE,
      check_inputs = TRUE)

### Arguments

`declaration` | A random sampling declaration, created by `declare_rs`.
`N` | The number of units. N must be a positive integer. (required)
`strata` | A vector of length N that indicates which stratum each unit belongs to.
`clusters` | A vector of length N that indicates which cluster each unit belongs to.
`n` | Use for a design in which n units (or clusters) are sampled. In a stratified design, exactly n units in each stratum will be sampled. (optional)
`prob` | Use for a design in which either floor(N*prob) or ceiling(N*prob) units (or clusters) are sampled. The probability of being sampled is exactly prob because with probability 1-prob, floor(N*prob) units (or clusters) will be sampled and with probability prob, ceiling(N*prob) units (or clusters) will be sampled. prob must be a real number between 0 and 1 inclusive. (optional)
`strata_n` | Use for a design in which strata_n describes the number of units to sample within each stratum.
`strata_prob` | Use for a design in which strata_prob describes the probability of being sampled within each stratum. Differs from prob in that the probability of being sampled can vary across strata.
`simple` | logical, defaults to FALSE. If TRUE, simple random sampling is used. When `simple = TRUE`, please do not specify n or strata_n. When `simple = TRUE`, `prob` may vary by unit.
`check_inputs` | logical. Defaults to TRUE.

### Examples

    # Draw a stratified random sample
    strata <- rep(c("A", "B","C"), times=c(50, 100, 200))

    declaration <- declare_rs(strata = strata)

    observed_probabilities <-
       obtain_inclusion_probabilities(declaration = declaration)

    table(strata, observed_probabilities)

    # Sometimes it is convenient to skip the declaration step
    observed_probabilities <-
       obtain_inclusion_probabilities(strata = strata)

    table(strata, observed_probabilities)

[Package randomizr version 0.16.1 Index]