Diagonal Label Comparison with NA Handling

Compares labels at corresponding positions (element-wise) between two equal-length vectors `a` and `b`, with explicit NA handling. Creates a sparse matrix with entries only on the diagonal.

Usage

diagonal_label_matrix_na(
  a,
  b,
  type = c("s", "d"),
  return_matrix = TRUE,
  dim1 = length(a),
  dim2 = length(b)
)

Arguments

a

The first categorical label vector.

b

The second categorical label vector. Must have same length as `a`.

type

The type of comparison: "s" for same labels (a[i] == b[i]) or "d" for different labels (a[i] != b[i]). Default is "s".

return_matrix

A logical flag indicating whether to return the result as a sparse matrix (default: TRUE) or a triplet matrix with columns (i, j, x).

dim1

The row dimension of the output matrix (default: length(a)).

dim2

The column dimension of the output matrix (default: length(b)).

Value

If return_matrix is TRUE, a sparse diagonal matrix where entry (i, i) is 1 if the labels at position i satisfy the comparison (and neither is NA). If return_matrix is FALSE, a 3-column matrix of (row, col, value) triplets.

Details

This function performs element-wise (positional) comparison, NOT all-pairs comparison. Positions where either label is NA are excluded from the result.

For all-pairs comparison (block structure), use binary_label_matrix. For diagonal comparison without NA handling, use diagonal_label_matrix.

See also

binary_label_matrix, diagonal_label_matrix

Examples

a <- c("x","y", NA)
b <- c("x","y","y")
diagonal_label_matrix_na(a, b, type="s", return_matrix=TRUE)
#> 3 x 3 sparse Matrix of class "dgCMatrix"
#>           
#> [1,] 1 . .
#> [2,] . 1 .
#> [3,] . . .