Coerce sparse data frame to sparse matrix

Turning data frame with sparse columns into sparse matrix using Matrix::sparseMatrix().

Usage

coerce_to_sparse_matrix(x)

Arguments

x

a data frame or tibble with sparse columns.

Details

No checking is currently do to x to determine whether it contains sparse columns or not. Thus it works with any data frame. Needless to say, creating a sparse matrix out of a dense data frame is not ideal.

See also

coerce_to_sparse_data_frame() coerce_to_sparse_tibble()

Examples

sparse_tbl <- lapply(1:10, function(x) sparse_double(x, x, length = 10))
names(sparse_tbl) <- letters[1:10]
sparse_tbl <- as.data.frame(sparse_tbl)
sparse_tbl
#>    a b c d e f g h i  j
#> 1  1 0 0 0 0 0 0 0 0  0
#> 2  0 2 0 0 0 0 0 0 0  0
#> 3  0 0 3 0 0 0 0 0 0  0
#> 4  0 0 0 4 0 0 0 0 0  0
#> 5  0 0 0 0 5 0 0 0 0  0
#> 6  0 0 0 0 0 6 0 0 0  0
#> 7  0 0 0 0 0 0 7 0 0  0
#> 8  0 0 0 0 0 0 0 8 0  0
#> 9  0 0 0 0 0 0 0 0 9  0
#> 10 0 0 0 0 0 0 0 0 0 10

res <- coerce_to_sparse_matrix(sparse_tbl)
res
#> 10 x 10 sparse Matrix of class "dgCMatrix"
#>   [[ suppressing 10 column names ‘a’, ‘b’, ‘c’ ... ]]
#>                        
#> 1  1 . . . . . . . .  .
#> 2  . 2 . . . . . . .  .
#> 3  . . 3 . . . . . .  .
#> 4  . . . 4 . . . . .  .
#> 5  . . . . 5 . . . .  .
#> 6  . . . . . 6 . . .  .
#> 7  . . . . . . 7 . .  .
#> 8  . . . . . . . 8 .  .
#> 9  . . . . . . . . 9  .
#> 10 . . . . . . . . . 10