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Extract arrays of multiple variables

Source: R/extract_list_of_variable_arrays.R
extract_list_of_variable_arrays.Rd

Extract arrays of draws for multiple variables, returning them as a named list of arrays. Each array has the same structure as returned by extract_variable_array.

Usage

extract_list_of_variable_arrays(x, variables = NULL, ...)

# Default S3 method
extract_list_of_variable_arrays(x, variables = NULL, ...)

# S3 method for class 'draws'
extract_list_of_variable_arrays(x, variables = NULL, ...)

Arguments

x

(draws) A draws object or another R object for which the method is defined.

variables

A character vector of variable names to extract, or NULL to extract all variables. To extract all dimensions from variables with indices (e.g. "x[1]"), provide the base variable names (e.g. "x").

...

Arguments passed to individual methods (if applicable).

Value

A named list of arrays, where each array has dimension niterations(x) x nchains(x) x any remaining dimensions determined by the indices of the variable x (if with_chains = TRUE) or dimension niterations(x) * nchains(x) x any remaining dimensions (if with_chains = FALSE).

See also

Other variable extraction methods: extract_variable(), extract_variable_array(), extract_variable_matrix()

Examples

x <- example_draws(example = "multi_normal")

# Extract multiple variables at once
vars <- extract_list_of_variable_arrays(x, c("mu", "Sigma"))
str(vars)
#> List of 2
#>  $ mu   : num [1:100, 1:4, 1:3] 0.18119 -0.03419 -0.05875 -0.1536 0.00989 ...
#>   ..- attr(*, "dimnames")=List of 3
#>   .. ..$ : NULL
#>   .. ..$ : NULL
#>   .. ..$ : NULL
#>  $ Sigma: num [1:100, 1:4, 1:3, 1:3] 1.2 1.14 1.12 1.14 1.19 ...
#>   ..- attr(*, "dimnames")=List of 4
#>   .. ..$ : NULL
#>   .. ..$ : NULL
#>   .. ..$ : NULL
#>   .. ..$ : NULL

# Extract all variables (uses base variable names)
all_vars <- extract_list_of_variable_arrays(x)
str(all_vars)
#> List of 2
#>  $ mu   : num [1:100, 1:4, 1:3] 0.18119 -0.03419 -0.05875 -0.1536 0.00989 ...
#>   ..- attr(*, "dimnames")=List of 3
#>   .. ..$ : NULL
#>   .. ..$ : NULL
#>   .. ..$ : NULL
#>  $ Sigma: num [1:100, 1:4, 1:3, 1:3] 1.2 1.14 1.12 1.14 1.19 ...
#>   ..- attr(*, "dimnames")=List of 4
#>   .. ..$ : NULL
#>   .. ..$ : NULL
#>   .. ..$ : NULL
#>   .. ..$ : NULL

# Extract specific indexed variables
vars2 <- extract_list_of_variable_arrays(x, c("mu[1]", "mu[2]"))
str(vars2)
#> List of 2
#>  $ mu[1]: num [1:100, 1:4, 1] 0.18119 -0.03419 -0.05875 -0.1536 0.00989 ...
#>   ..- attr(*, "dimnames")=List of 3
#>   .. ..$ : NULL
#>   .. ..$ : NULL
#>   .. ..$ : NULL
#>  $ mu[2]: num [1:100, 1:4, 1] 0.467 0.0926 0.3904 -0.072 -0.2544 ...
#>   ..- attr(*, "dimnames")=List of 3
#>   .. ..$ : NULL
#>   .. ..$ : NULL
#>   .. ..$ : NULL