Constructs a mapper descriptor for the **dense rendering / anchor pipeline** — used when projecting subject-space voxel/parcel values onto a set of 3-D spatial anchor points (e.g., medoid centroids). Pass the result to [dkge_build_renderer()], [dkge_render_subject_values()], or directly to [fit_mapper()] together with `subj_points` / `anchor_points` matrices.
Use [dkge_mapper_spec()] instead when you need a **transport pipeline mapper** that operates in an abstract feature space (ridge regression, Sinkhorn OT over embeddings) for functions such as [dkge_prepare_transport()] or [dkge_transport_spec()].
Usage
dkge_mapper(type = c("knn", "sinkhorn", "ridge", "gw"), ...)Arguments
- type
Mapper backend identifier: `"knn"` (barycentric kNN, fully implemented), `"sinkhorn"` (OT over point clouds), `"ridge"`, or `"gw"` (Gromov-Wasserstein; latter three require external plugins).
- ...
Backend-specific parameters stored within the mapper object (e.g. `k`, `sigx`, `sigz` for kNN; `epsilon` for Sinkhorn).
Examples
spec <- dkge_mapper(type = "knn", k = 3, sigx = 1)
subj_points <- matrix(rnorm(12 * 3), 12, 3)
anchor_points <- matrix(rnorm(6 * 3), 6, 3)
fit <- fit_mapper(spec, subj_points = subj_points, anchor_points = anchor_points)
y_anchor <- apply_mapper(fit, rnorm(nrow(subj_points)))
length(y_anchor)
#> [1] 6