R: probabilities of assignment: Simple Random Assignment

simple_ra_probabilities {randomizr} | R Documentation

## probabilities of assignment: Simple Random Assignment

### Description

probabilities of assignment: Simple Random Assignment

### Usage

    simple_ra_probabilities(N, prob = NULL, prob_unit = NULL,
      prob_each = NULL, num_arms = NULL, conditions = NULL,
      check_inputs = TRUE, simple = TRUE)

### Arguments

`N` | The number of units. N must be a positive integer. (required)
`prob` | Use for a two-arm design. prob is the probability of assignment to treatment and must be a real number between 0 and 1 inclusive and must be length 1. (optional)
`prob_unit` | Use for a two-arm design. prob is the probability of assignment to treatment and must be a real number between 0 and 1 inclusive and must be length N. (optional)
`prob_each` | Use for a multi-arm design in which the values of prob_each determine the probabilities of assignment to each treatment condition. prob_each must be a numeric vector giving the probability of assignment to each condition. All entries must be nonnegative real numbers between 0 and 1 inclusive and the total must sum to 1. It may be a conditions-length vector or a N-by-conditions matrix. (optional)
`num_arms` | The number of treatment arms. If unspecified, num_arms will be determined from the other arguments. (optional)
`conditions` | A character vector giving the names of the treatment groups. If unspecified, the treatment groups will be named 0 (for control) and 1 (for treatment) in a two-arm trial and T1, T2, T3, in a multi-arm trial. An exception is a two-group design in which num_arms is set to 2, in which case the condition names are T1 and T2, as in a multi-arm trial with two arms. (optional)
`check_inputs` | logical. Defaults to TRUE.
`simple` | logical. internal use only.

### Value

A matrix of probabilities of assignment

### Examples

    # Two Group Designs
    prob_mat <- simple_ra_probabilities(N=100)
    head(prob_mat)

    prob_mat <- simple_ra_probabilities(N=100, prob=0.5)
    head(prob_mat)

    prob_mat <- simple_ra_probabilities(N=100, prob_each = c(0.3, 0.7),
                            conditions = c("control", "treatment"))
    head(prob_mat)

    # Multi-arm Designs
    prob_mat <- simple_ra_probabilities(N=100, num_arms=3)
    head(prob_mat)

    prob_mat <- simple_ra_probabilities(N=100, prob_each=c(0.3, 0.3, 0.4))
    head(prob_mat)

    prob_mat <- simple_ra_probabilities(N=100, prob_each=c(0.3, 0.3, 0.4),
                            conditions=c("control", "placebo", "treatment"))
    head(prob_mat)

    prob_mat <- simple_ra_probabilities(N=100, conditions=c("control", "placebo", "treatment"))
    head(prob_mat)

[Package randomizr version 0.18.0 Index]