Select a matrix or spatial execution path — execution

Matrix operations always use bounded observation-by-feature blocks. Spatial operations use a source's native-image capability only when the frame view retains the complete feature domain; otherwise they reconstruct maps from packed assay values through the frame's feature space.

Usage

execution_path(
  x,
  operation = c("matrix", "spatial"),
  assay = active_assay(x),
  path = c("auto", "native", "reconstruct")
)

Arguments

x: An fmri_frame or view.
operation: Either "matrix" or "spatial".
assay: Assay name.
path: For spatial operations, one of "auto", "native", or "reconstruct".

Value

One of "matrix", "native", or "reconstruct".

Examples

sp <- volume_space(dim = c(2L, 2L, 1L), affine = diag(4), support = 1:4)
frame <- fmri_frame(
  assays = list(signal = memory_source(matrix(seq_len(12), 3, 4))),
  observations = data.frame(.obs_id = sprintf("obs-%d", 1:3)),
  space = sp,
  active_assay = "signal"
)
execution_path(frame, operation = "matrix")
#> [1] "matrix"
execution_path(frame, operation = "spatial")
#> [1] "reconstruct"