The draws_matrix format

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

as_draws_matrix(x, ...)

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

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

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

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

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

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

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

draws_matrix(...)

is_draws_matrix(x)

Arguments

x	An object to convert to a draws_matrix object.
...	For as_draws_matrix(): Arguments passed to individual methods (if applicable). For draws_matrix(): Named arguments containing numeric vectors each defining a separate variable.

Value

A draws_matrix object, which has classes c("draws_matrix", "draws", "matrix").

Details

Objects of class "draws_matrix" are matrices (2-D arrays) with dimensions "draw" and "variable". This format does not store any information about which MCMC chain the draws are from and so we simply refer to the rows as draws and not iterations (unlike for the draws_array format). See Examples.

See also

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

Examples

x1 <- as_draws_matrix(example_draws())
class(x1)
#> [1] "draws_matrix" "draws"        "matrix"      
print(x1)
#> # A draws_matrix: 400 draws, and 10 variables
#>     variable
#> draw   mu tau theta[1] theta[2] theta[3] theta[4] theta[5] theta[6]
#>   1  2.01 2.8     3.96    0.271    -0.74      2.1    0.923      1.7
#>   2  1.46 7.0     0.12   -0.069     0.95      7.3   -0.062     11.3
#>   3  5.81 9.7    21.25   14.931     1.83      1.4    0.531      7.2
#>   4  6.85 4.8    14.70    8.586     2.67      4.4    4.758      8.1
#>   5  1.81 2.8     5.96    1.156     3.11      2.0    0.769      4.7
#>   6  3.84 4.1     5.76    9.909    -1.00      5.3    5.889     -1.7
#>   7  5.47 4.0     4.03    4.151    10.15      6.6    3.741     -2.2
#>   8  1.20 1.5    -0.28    1.846     0.47      4.3    1.467      3.3
#>   9  0.15 3.9     1.81    0.661     0.86      4.5   -1.025      1.1
#>   10 7.17 1.8     6.08    8.102     7.68      5.6    7.106      8.5
#> # ... with 390 more draws, and 2 more variables
str(x1)
#>  'draws_matrix' num [1:400, 1:10] 2.01 1.46 5.81 6.85 1.81 ...
#>  - attr(*, "dimnames")=List of 2
#>   ..$ draw    : chr [1:400] "1" "2" "3" "4" ...
#>   ..$ variable: chr [1:10] "mu" "tau" "theta[1]" "theta[2]" ...

x2 <- draws_matrix(a = rnorm(10), b = rnorm(10), c = 1)
class(x2)
#> [1] "draws_matrix" "draws"        "matrix"      
print(x2)
#> # A draws_matrix: 10 draws, and 3 variables
#>     variable
#> draw      a     b c
#>   1   0.424 -0.39 1
#>   2   1.063 -0.79 1
#>   3   1.049 -1.06 1
#>   4  -0.038 -0.80 1
#>   5   0.486 -1.76 1
#>   6   1.673 -0.69 1
#>   7  -0.354 -0.56 1
#>   8   0.946 -0.54 1
#>   9   1.317  0.23 1
#>   10 -0.297  0.98 1
str(x2)
#>  'draws_matrix' num [1:10, 1:3] 0.4242 1.0631 1.0487 -0.0381 0.4861 ...
#>  - attr(*, "dimnames")=List of 2
#>   ..$ draw    : chr [1:10] "1" "2" "3" "4" ...
#>   ..$ variable: chr [1:3] "a" "b" "c"