segmentTulipLeafChoice: Segment Tulip Leaf Choice

In alcyon: Spatial Network Analysis

Segment Tulip Leaf Choice

Description

This is the legacy calculation of choice where backwards traversal was only started from "leaf" nodes i.e. nodes where the forwards traversal originally found a dead end (from actual dead ends, to dead ends because the next line has been covered through a different path)

Usage

segmentTulipLeafChoice(
  map,
  radii,
  radiusTraversalType,
  weightByAttribute = NULL,
  quantizationWidth = NA,
  selectedOriginRefs = NULL,
  recordSelLeafs = FALSE,
  copyMap = TRUE,
  verbose = FALSE,
  progress = FALSE
)

Arguments

map	A Segment ShapeGraph
radii	A list of radii
radiusTraversalType	The traversal type to keep track of whether the analysis is within the each radius limit. See TraversalType
weightByAttribute	The attribute to weigh the analysis with
quantizationWidth	Set this to use chunks of this width instead of continuous values for the cost of traversal. This is equivalent to the "tulip bins" for depthmapX's tulip analysis (1024 tulip bins = pi/1024 quantizationWidth). Only works for Segment ShapeGraphs
selectedOriginRefs	Optional. Limit the analysis to specific refs
recordSelLeafs	Record the leaf column of the selected refs
copyMap	Optional. Copy the internal sala map
verbose	Optional. Show more information of the process.
progress	Optional. Enable progress display

Value

A new map with the results included

Examples

# LatticeMap analysis (VGA)
mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  latticeMap <- makeVGALatticeMap(
    sfMap,
    gridSize = 0.5,
    fillX = 3.0,
    fillY = 6.0,
    maxVisibility = NA,
    boundaryGraph = FALSE,
    verbose = FALSE
  )
allToAllTraverse(latticeMap,
  traversalType = TraversalType$Angular,
  radii = -1L,
  radiusTraversalType = TraversalType$None
)

# Axial analysis
mifFile <- system.file(
    "extdata", "testdata", "barnsbury",
    "barnsbury_small_axial_original.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeGraph <- as(sfMap, "AxialShapeGraph")
allToAllTraverse(
  shapeGraph,
  traversalType = TraversalType$Topological,
  radii = c("n", "3"),
  includeBetweenness = TRUE
)

# Segment analysis
mifFile <- system.file(
    "extdata", "testdata", "barnsbury",
    "barnsbury_small_segment_original.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeGraph <- as(sfMap, "SegmentShapeGraph")
segmentTulipLeafChoice(
  shapeGraph,
  radii = c("n", "100"),
  radiusTraversalType = TraversalType$Metric,
  weightByAttribute = "Segment Length",
  quantizationWidth = pi / 1024L,
  verbose = FALSE,
  progress = FALSE
)

alcyon documentation built on Aug. 30, 2026, 1:07 a.m.