Apply UOT coupling as a barycentric map (sparse, matrix signal via CSC) — uot_apply_map_sparse_mat

Sparse matrix version for time series or multi-contrast signals. Requires a CSC representation of the cost graph (column pointers + row indices).

Usage

uot_apply_map_sparse_mat_cpp(
  col_ptr,
  row_idx,
  cost_csc,
  n_rows,
  n_cols,
  alpha,
  beta,
  fbar,
  gbar,
  epsilon,
  signal,
  delta = 1e-08
)

Arguments

col_ptr: Integer vector of length m+1 with CSC column offsets (0-based or 1-based accepted; if 1-based, it must start at 0 or 1 and be nondecreasing).
row_idx: Integer vector of length nnz giving 1-based row indices.
cost_csc: Numeric vector of length nnz aligned with `row_idx`.
n_rows: Number of source nodes.
n_cols: Number of target nodes.
alpha: Source masses (length n_rows).
beta: Target masses (length n_cols).
fbar: Translation-invariant source potential (length n_rows).
gbar: Translation-invariant target potential (length n_cols).
epsilon: Entropic regularization parameter (> 0).
signal: Source signal matrix (T x n_rows).
delta: Stabilizer added to the denominator.

Value

A numeric matrix (T x n_cols) in template space.

Details

This computes \(\hat S = S W / (\pi_2 + \delta)\) without materializing the full \(\pi\). The implementation uses per-column log-stabilization to avoid overflow in the exponential weights.