Create a tidy correlation structure

Usage

correlation_structure(
  n_variables,
  rho = 0,
  structure = c("independent", "exchangeable", "ar1", "custom"),
  correlation = NULL,
  variable_names = NULL
)

Arguments

n_variables: Number of variables.
rho: Correlation coefficient used by exchangeable and AR(1) structures.
structure: Correlation structure: one of "independent", "exchangeable", "ar1", or "custom". If left unset it is chosen from the other arguments: "custom" when correlation is supplied, "exchangeable" when a non-zero rho is supplied, and "independent" otherwise. Passing "independent" together with a non-zero rho is a contradiction and raises a simulab_contradictory_structure error.
correlation: Custom correlation matrix.
variable_names: Optional variable names.

Value

A base data.frame with one row per matrix cell and columns row, column, and correlation.

Examples

correlation_structure(
  n_variables = 3,
  rho = 0.5,
  structure = "ar1"
)
#>   row column correlation
#> 1  V1     V1        1.00
#> 2  V2     V1        0.50
#> 3  V3     V1        0.25
#> 4  V1     V2        0.50
#> 5  V2     V2        1.00
#> 6  V3     V2        0.50
#> 7  V1     V3        0.25
#> 8  V2     V3        0.50
#> 9  V3     V3        1.00