The draws_array format

The as_draws_array() methods convert objects to the draws_array format. The draws_array() function creates an object of the draws_array format based on a set of numeric vectors. See Details.

as_draws_array(x, ...)

# S3 method for default
as_draws_array(x, ...)

# S3 method for draws_array
as_draws_array(x, ...)

# S3 method for draws_matrix
as_draws_array(x, ...)

# S3 method for draws_df
as_draws_array(x, ...)

# S3 method for draws_list
as_draws_array(x, ...)

# S3 method for mcmc
as_draws_array(x, ...)

# S3 method for mcmc.list
as_draws_array(x, ...)

draws_array(..., .nchains = 1)

is_draws_array(x)

Arguments

x	An object to convert to a draws_array object.
...	For as_draws_array(): Arguments passed to individual methods (if applicable). For draws_array(): Named arguments containing numeric vectors each defining a separate variable.
.nchains	Number of chains (default is 1).

Value

A draws_array object, which has classes c("draws_array", "draws", "array").

Details

Objects of class "draws_array" are 3-D arrays with dimensions "iteration", "chain", and "variable". See Examples.

See also

Other formats: draws_df(), draws_list(), draws_matrix(), draws

Examples

x1 <- as_draws_array(example_draws())
class(x1)
#> [1] "draws_array" "draws"       "array"      
print(x1)
#> # A draws_array: 100 iterations, 4 chains, and 10 variables
#> , , variable = mu
#> 
#>          chain
#> iteration   1    2     3   4
#>         1 2.0  3.0  1.79 6.5
#>         2 1.5  8.2  5.99 9.1
#>         3 5.8 -1.2  2.56 0.2
#>         4 6.8 10.9  2.79 3.7
#>         5 1.8  9.8 -0.03 5.5
#> 
#> , , variable = tau
#> 
#>          chain
#> iteration   1    2    3   4
#>         1 2.8 2.80  8.7 3.8
#>         2 7.0 2.76  2.9 6.8
#>         3 9.7 0.57  8.4 5.3
#>         4 4.8 2.45  4.4 1.6
#>         5 2.8 2.80 11.0 3.0
#> 
#> , , variable = theta[1]
#> 
#>          chain
#> iteration     1     2    3     4
#>         1  3.96  6.26 13.3  5.78
#>         2  0.12  9.32  6.3  2.09
#>         3 21.25 -0.97 10.6 15.72
#>         4 14.70 12.45  5.4  2.69
#>         5  5.96  9.75  8.2 -0.91
#> 
#> , , variable = theta[2]
#> 
#>          chain
#> iteration      1    2   3   4
#>         1  0.271  1.0 2.1 5.0
#>         2 -0.069  9.4 7.3 8.2
#>         3 14.931 -1.2 5.7 6.0
#>         4  8.586 12.5 2.8 2.7
#>         5  1.156 11.9 3.2 3.2
#> 
#> # ... with 95 more iterations, and 6 more variables
str(x1)
#>  'draws_array' num [1:100, 1:4, 1:10] 2.01 1.46 5.81 6.85 1.81 ...
#>  - attr(*, "dimnames")=List of 3
#>   ..$ iteration: chr [1:100] "1" "2" "3" "4" ...
#>   ..$ chain    : chr [1:4] "1" "2" "3" "4"
#>   ..$ variable : chr [1:10] "mu" "tau" "theta[1]" "theta[2]" ...

x2 <- draws_array(a = rnorm(10), b = rnorm(10), c = 1)
class(x2)
#> [1] "draws_array" "draws"       "array"      
print(x2)
#> # A draws_array: 10 iterations, 1 chains, and 3 variables
#> , , variable = a
#> 
#>          chain
#> iteration    1
#>         1 0.94
#>         2 0.18
#>         3 0.24
#>         4 1.62
#>         5 0.11
#> 
#> , , variable = b
#> 
#>          chain
#> iteration     1
#>         1  0.07
#>         2 -0.64
#>         3 -0.05
#>         4 -0.25
#>         5  0.44
#> 
#> , , variable = c
#> 
#>          chain
#> iteration 1
#>         1 1
#>         2 1
#>         3 1
#>         4 1
#>         5 1
#> 
#> # ... with 5 more iterations
str(x2)
#>  'draws_array' num [1:10, 1, 1:3] 0.935 0.176 0.244 1.624 0.112 ...
#>  - attr(*, "dimnames")=List of 3
#>   ..$ iteration: chr [1:10] "1" "2" "3" "4" ...
#>   ..$ chain    : chr "1"
#>   ..$ variable : chr [1:3] "a" "b" "c"