butterfly {AMAPVox}

Identify butterflies from a VoxelSpace object.

Description

Identify butterflies from a VoxelSpace object.

A butterfly refers to a non-empty isolated voxel. Non-empty means that there is one or more hits recorded in the voxel. Isolated means that voxels in the Moore neighborhood of rank 1 are empty (no hit).

Usage

butterfly(vxsp)

Arguments

vxsp

a VoxelSpace object

Value

a list of voxel index (i, j, k) identified as butterfly.

See Also

clear()

Examples

# load a voxel file
vxsp <- readVoxelSpace(system.file("extdata", "tls_sample.vox", package = "AMAPVox"))
# identify butterflies
btf <- butterfly(vxsp)
# clear butterflies
clear(vxsp, butterfly(vxsp))