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Cluster4d using SLIC method

Source: R/cluster4d.R
cluster4d_slic.Rd

Wrapper for SLIC algorithm with standardized interface.

Usage

cluster4d_slic(
  vec,
  mask,
  n_clusters = 100,
  spatial_weight = 0.5,
  max_iterations = 10,
  connectivity = 26,
  parallel = TRUE,
  verbose = FALSE,
  preserve_k = FALSE,
  seed_relocate = "none",
  ...,
  .input_contract = NULL
)

Arguments

vec

A NeuroVec instance supplying the 4D data (x, y, z, time) to cluster

mask

A NeuroVol mask defining the voxels to include in clustering. Values must be finite. Voxels are included exactly when the mask value is strictly greater than zero; zero and negative values are excluded.

n_clusters

Finite integer target number of clusters (default 100), from one through the number of included mask voxels. Note that some methods may produce slightly different numbers of clusters due to algorithmic constraints.

spatial_weight

Method-specific spatial control in [0, 1]. For methods that define a convex feature/spatial blend, zero disables the spatial term and one disables the feature term. Other methods use the value as a bounded mapping to a native scale; their endpoints do not have that blend meaning. Default 0.5. This parameter is inactive for "rena" and "rena_plus"; supplying it explicitly for either method is an error. Maps to method-specific parameters:

  • supervoxels: alpha = 1 - spatial_weight (0 = all spatial, 1 = all feature)

  • snic: compactness = spatial_weight * 10 (range 0-10)

  • slic: compactness = spatial_weight * 20 (typical range 1-20)

  • corr_slic/brs_slic: direct convex blend between correlation and scaled spatial distance

  • slice_msf: compactness = spatial_weight * 10, followed by FH component scale 2 / (compactness + 1). This changes the graph-segmentation scale; it is not a convex spatial/feature blend.

  • flash3d: lambda_s = spatial_weight (direct mapping)

  • mcl: direct blend between feature and spatial edge similarities

max_iterations

Positive finite integer iteration limit for iterative methods. It is inactive for "snic", "slice_msf", and "commute"; supplying it explicitly for those methods is an error.

connectivity

Integer neighborhood connectivity. Supported values are method-specific: supervoxels accepts 6, 18, 26, or 27; slic, corr_slic, brs_slic, and slice_msf accept 6 or 26; G3S, ReNA variants, and MCL accept 6, 18, or 26. It is inactive for snic, flash3d, acsc, and commute.

parallel

Enable parallel processing for supervoxels and slic. For all other methods, an explicit TRUE is rejected; omitted or FALSE selects the serial implementation. Default TRUE for supported methods.

verbose

Print progress messages. Default FALSE.

preserve_k

Request exactly K connected clusters. Exact K is feasible only when K is at least the number of connected mask components; below that topological minimum, connectivity takes precedence and the minimum feasible cluster count is returned with a warning.

seed_relocate

Seed relocation method

...

Additional parameters passed to slic4d_supervoxels

.input_contract

Internal prevalidated input receipt used by cluster4d(); direct callers should leave this as NULL.

Value

A cluster4d_result object