alcyon (version 0.7.0)

allToAllTraverse: All-to-all traversal

Description

Runs all-to-all traversal on a map with a graph. This is applicable to:

• PointMaps (Visibility Graph Analysis)

• Axial ShapeGraphs (Axial analysis)

• Segment ShapeGraphs (Segment analysis)

Usage

allToAllTraverse(
  map,
  traversalType,
  radii,
  radiusTraversalType,
  weightByAttribute = NULL,
  includeBetweenness = FALSE,
  quantizationWidth = NA,
  gatesOnly = FALSE,
  nthreads = 1L,
  copyMap = TRUE,
  verbose = FALSE,
  progress = FALSE
)

Value

A new map with the results included

Arguments

map

A PointMap, Axial ShapeGraph or Segment ShapeGraph

traversalType

The traversal type. See TraversalType

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

includeBetweenness

Set to TRUE to also calculate betweenness (known as Choice in the Space Syntax domain)

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

gatesOnly

Optional. Only calculate results at particular gate pixels. Only works for PointMaps

nthreads

Optional. Use more than one threads. 1 by default, set to 0 to use all available. Only available for PointMaps.

copyMap

Optional. Copy the internal sala map

verbose

Optional. Show more information of the process.

progress

Optional. Enable progress display

Examples

# Pointmap analysis (VGA)
mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  pointMap <- makeVGAPointMap(
    sfMap,
    gridSize = 0.5,
    fillX = 3.0,
    fillY = 6.0,
    maxVisibility = NA,
    boundaryGraph = FALSE,
    verbose = FALSE
  )
allToAllTraverse(pointMap,
  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")
allToAllTraverse(
  shapeGraph,
  radii = c("n", "100"),
  radiusTraversalType = TraversalType$Metric,
  traversalType = TraversalType$Angular,
  weightByAttribute = "Segment Length",
  includeBetweenness = TRUE,
  quantizationWidth = pi / 1024L,
  verbose = FALSE,
  progress = FALSE
)