Create a FeaturedSpace from a streaming background provider

Builds a FeaturedSpace by draining a callback-style background provider (typically backed by a terra::SpatRaster block loop) one tile at a time, then constructing features from the concatenated (num_points x num_layers) matrix via generate_features.

Usage

maxent_featured_space_from_callback(
  num_points,
  num_layers,
  layer_names,
  sample_indices,
  feature_types,
  n_thresholds,
  n_hinges,
  next_tile_fn,
  reset_fn,
  use_cache = TRUE
)

Arguments

num_points

Integer: total number of finite background points the provider will emit (sum of nrow() across tiles).

num_layers

Integer: number of environmental variables / raster layers per tile row.

layer_names

Character vector of length num_layers giving the name for each layer / column (used when generating feature names such as bio1^2, bio1*bio2).

sample_indices

Integer vector: 0-based indices of occurrence samples in the concatenated background stream.

feature_types

Character vector of feature types to generate. See maxent_generate_features.

n_thresholds

Number of threshold knots per variable.

n_hinges

Number of hinge knots per variable.

next_tile_fn

R function returning the next tile as a numeric matrix (nrow x num_layers), or a 0-row matrix / NULL when the stream is exhausted. The function is responsible for filtering out rows containing NAs.

reset_fn

R function (no arguments) that rewinds the underlying stream to the beginning.

use_cache

Logical; wrap the callback stream in CachingBackgroundProvider.

Value

External pointer to a FeaturedSpace object.

Details

This is the C++ entry point used by maxent_featured_space_from_rast; end users should prefer that R-level wrapper.