Package 'alcyon'

Title: Spatial Network Analysis
Description: Interface package for 'sala', the spatial network analysis library from the 'depthmapX' software application. The R parts of the code are based on the 'rdepthmap' package. Allows for the analysis of urban and building-scale networks and provides metrics and methods usually found within the Space Syntax domain. Methods in this package are described by K. Al-Sayed, A. Turner, B. Hillier, S. Iida and A. Penn (2014) "Space Syntax methodology", and also by A. Turner (2004) <https://discovery.ucl.ac.uk/id/eprint/2651> "Depthmap 4: a researcher's handbook".
Authors: Petros Koutsolampros [cre, aut] (<https://orcid.org/0000-0003-2842-9899>, 'sala' library contributor through 'depthmapX'), Fani Kostourou [ctb] , Kimon Krenz [ctb] , Alasdair Turner [ctb] ('sala' library contributor through 'depthmapX'), Tasos Varoudis [ctb] (<https://orcid.org/0000-0001-7790-5623>, 'sala' library contributor through 'depthmapX'), Christian Sailer [ctb] ('sala' library contributor through 'depthmapX'), Eva Friedrich [ctb] ('sala' library contributor through 'depthmapX'), University College London [fnd, cph] (2015 - 2020), Spacelab UK [fnd] (2015 - 2020)
Maintainer: Petros Koutsolampros <[email protected]>
License: GPL-3
Version: 0.7.0
Built: 2025-02-21 02:54:26 UTC
Source: https://github.com/spatialnous/alcyon

Help Index

Agent Analysis

Description

Runs Agent Analysis on the given PointMap

Usage

agentAnalysis(
  pointMap,
  timesteps,
  releaseRate,
  agentLifeTimesteps,
  agentFov,
  agentStepsToDecision,
  agentLookMode,
  originX = vector(),
  originY = vector(),
  locationSeed = 0L,
  numberOfTrails = 0L,
  getGateCounts = FALSE,
  copyMap = TRUE,
  verbose = FALSE,
  progress = FALSE
)

Arguments

pointMap

A PointMap, used as an exosomatic visual map for agents to take exploratory information
timesteps

Number of total system timesteps.
releaseRate

Agent release rate (likelihood of release per timestep).
agentLifeTimesteps

Agent total lifetime (in timesteps)
agentFov

Agent field-of-view (out of 32 bins = 360).
agentStepsToDecision

Agent steps before turn decision.
agentLookMode

The agent look mode. See AgentLookMode
originX

Agent starting points (x coordinates).
originY

Agent starting point (y coordinates).
locationSeed

Agents to start at random locations with specific seed (0 to 10). Default is 0.
numberOfTrails

Record trails for this amount of agents (set to 0 to record all, with max possible currently = 50).
getGateCounts

Get values at gates
copyMap

Optional. Copy the internal sala map
verbose

Optional. Show more information of the process.
progress

Optional. Show process progress.

Value

Returns a list with:

  • newAttributes: The new attributes that were created during the process

  • trailMap: A ShapeMap with trails if numberOfTrails was set over 0

Examples

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
  )
agentAnalysis(
  pointMap,
  timesteps = 3000L,
  releaseRate = 0.1,
  agentStepsToDecision = 3L,
  agentFov = 11L,
  agentLife = 1000L,
  agentLookMode = AgentLookMode$Standard,
  originX = NA,
  originY = NA,
  locationSeed = 1L,
  numberOfTrails = 50L,
  getGateCounts = FALSE,
  verbose = FALSE
)

Agent look modes.

Description

These are meant to be used to indicate what kind of look function the agents use to look around and decide where to go next. Possible values:

  • AgentLookMode$None

  • AgentLookMode$Standard

  • AgentLookMode$LineOfSightLength

  • AgentLookMode$OcclusionLength

  • AgentLookMode$OcclusionAny

  • AgentLookMode$OcclusionGroup45 (Occlusion group bins - 45 degrees)

  • AgentLookMode$OcclusionGroup60 (Occlusion group bins - 60 degrees)

  • AgentLookMode$OcclusionFurthest (Furthest occlusion per bin)

  • AgentLookMode$BinFarDistance (Per bin far distance weighted)

  • AgentLookMode$BinAngle (Per bin angle weighted)

  • AgentLookMode$BinFarDistanceAngle (Per bin far-distance and angle weighted)

  • AgentLookMode$BinMemory (Per bin memory)

Usage

AgentLookMode

Format

An object of class list of length 12.

Value

A list of numbers representing each agent look mode

Examples

AgentLookMode$Standard
AgentLookMode$LineOfSightLength
AgentLookMode$OcclusionAny

All-line Axial ShapeGraph

Description

A representation of sala's All-line ShapeGraph in R. Holds onto a sala All-line ShapeGraph pointer and operates on that

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
)

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

Value

A new map with the results included

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
)

as("sf", "ShapeMap")

Description

This is a direct conversion, for ShapeMap -> Axial -> Segment see axialToSegmentShapeGraph

This is a direct conversion, for ShapeMap -> Axial -> Segment see axialToSegmentShapeGraph

See Also

Other ShapeMap: ShapeMap-class

Other ShapeMap: ShapeMap-class

Other AxialShapeGraph: AxialShapeGraph-class

Other AxialShapeGraph: AxialShapeGraph-class

Other SegmentShapeGraph: SegmentShapeGraph-class

Other SegmentShapeGraph: SegmentShapeGraph-class

Axial analysis - local metrics

Description

Runs axial analysis to get the local metrics Control and Controllability

Usage

axialAnalysisLocal(shapeGraph, copyMap = TRUE, verbose = FALSE)

Arguments

shapeGraph

An Axial ShapeGraph
copyMap

Optional. Copy the internal sala map
verbose

Optional. Show more information of the process.

Value

Returns a list with:

  • completed: Whether the analysis completed

  • newAttributes: The new attributes that were created during the process

Examples

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")
axialAnalysisLocal(shapeGraph)

Subset AxialShapeGraph objects

Description

Subsetting AxialShapeGraph objects essentially passes the data to sf. See sf

Usage

## S3 method for class 'AxialShapeGraph'
x[...]

## S3 replacement method for class 'AxialShapeGraph'
x[...] <- value

Arguments

x

object of class AxialShapeGraph passed to stars[]
...

other parameters passed to stars[] <-

value

value to be passed to sf[] <-

Axial ShapeGraph

Description

A representation of sala's Axial ShapeGraph in R. Holds onto a sala Axial ShapeGraph pointer and operates on that

See Also

Other AxialShapeGraph: as()

Axial to Segment ShapeGraph

Description

Convert an Axial ShapeGraph to a Segment ShapeGraph

Usage

axialToSegmentShapeGraph(axialShapeGraph, stubRemoval = NULL)

Arguments

axialShapeGraph

An Axial ShapeGraph
stubRemoval

Remove stubs of axial lines shorter than this percentage (for example provide 0.4 for 40%)

Value

A new Segment ShapeGraph

Examples

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")
axialToSegmentShapeGraph(shapeGraph, stubRemoval = 0.4)

Block lines on a PointMap

Description

Takes a PointMap and a ShapeMap with lines and blocks the cells on the PointMap where the lines pass.

Usage

blockLines(pointMap, lineStringMap, copyMap = TRUE, verbose = FALSE)

Arguments

pointMap

The input PointMap
lineStringMap

Map of lines, either a ShapeMap, or an sf lineString map
copyMap

Optional. Copy the internal sala map
verbose

Optional. Show more information of the process.

Value

A new PointMap with points as they have been blocked by the lines

Examples

mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeMap <- as(sfMap[, vector()], "ShapeMap")
lineStringMap <- as(sfMap, "sf")
mapRegion <- sf::st_bbox(lineStringMap)
pointMap <- createGrid(
  minX = mapRegion[["xmin"]],
  minY = mapRegion[["ymin"]],
  maxX = mapRegion[["xmax"]],
  maxY = mapRegion[["ymax"]],
  gridSize = 0.04
)
blockLines(
  pointMap = pointMap,
  lineStringMap = lineStringMap[vector()]
)

Get map connections

Description

Get map connections

Usage

connections(map)

Arguments

map

A sala map

Value

A matrix with the connected refs

Get the Axial ShapeGraph connections

Description

Get the Axial ShapeGraph connections

Usage

## S4 method for signature 'AxialShapeGraph'
connections(map)

Arguments

map

An Axial ShapeGraph

Value

A matrix with the connected refs

Examples

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")
connections(shapeGraph)

Get the PointMap connections

Description

Get the PointMap connections

Usage

## S4 method for signature 'PointMap'
connections(map)

Arguments

map

A PointMap

Value

A matrix with the connected refs

Examples

mifFile <- system.file(
    "extdata", "testdata", "gallery",
    "gallery_lines.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  pointMap <- makeVGAPointMap(
    sfMap,
    gridSize = 0.04,
    fillX = 3.01,
    fillY = 6.7,
    maxVisibility = NA,
    boundaryGraph = FALSE,
    verbose = FALSE
  )
# plot the first 100 connections only
head(connections(pointMap), 100)

Get the Segment ShapeGraph connections

Description

Get the Segment ShapeGraph connections

Usage

## S4 method for signature 'SegmentShapeGraph'
connections(map)

Arguments

map

An Segment ShapeGraph

Value

A matrix with the connected refs

Examples

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")
connections(shapeGraph)

Create a PointMap through a grid

Description

Create a PointMap through a grid

Usage

createGrid(minX, minY, maxX, maxY, gridSize, verbose = FALSE)

Arguments

minX

Minimum X of the bounding region
minY

Minimum Y of the bounding region
maxX

Maximum X of the bounding region
maxY

Maximum Y of the bounding region
gridSize

Size of the cells
verbose

Optional. Show more information of the process.

Value

A new PointMap

Examples

mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeMap <- as(sfMap[, vector()], "ShapeMap")
lineStringMap <- as(sfMap, "sf")
mapRegion <- sf::st_bbox(lineStringMap)
createGrid(
  minX = mapRegion[["xmin"]],
  minY = mapRegion[["ymin"]],
  maxX = mapRegion[["xmax"]],
  maxY = mapRegion[["ymax"]],
  gridSize = 0.04
)

Fill a PointMap's grid starting from one or more points

Description

Fill a PointMap's grid starting from one or more points

Usage

fillGrid(pointMap, fillX, fillY, copyMap = TRUE, verbose = FALSE)

Arguments

pointMap

The input PointMap
fillX

X coordinate of the fill points
fillY

Y coordinate of the fill points
copyMap

Optional. Copy the internal sala map
verbose

Optional. Show more information of the process.

Value

A new PointMap with filled points

Examples

mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeMap <- as(sfMap[, vector()], "ShapeMap")
lineStringMap <- as(sfMap, "sf")
mapRegion <- sf::st_bbox(lineStringMap)
pointMap <- createGrid(
  minX = mapRegion[["xmin"]],
  minY = mapRegion[["ymin"]],
  maxX = mapRegion[["xmax"]],
  maxY = mapRegion[["ymax"]],
  gridSize = 0.04
)
pointMap <- blockLines(
  pointMap = pointMap,
  lineStringMap = lineStringMap[vector()]
)
fillGrid(
  pointMap = pointMap,
  fillX = 3.01,
  fillY = 6.7
)

Extract top x percent of features

Description

Sorts features by a specific column and extracts the top x percent

Usage

getTopFeatures(lineStringMap, column, percent)

Arguments

lineStringMap

An sf lineString map
column

The column to use to extract the features from
percent

Percentage of features (to total) to extract

Value

The lineString map filtered and sorted

Examples

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")
shapeGraph <- allToAllTraverse(
  shapeGraph,
  traversalType = TraversalType$Topological,
  radii = c("n", "3"),
  includeBetweenness = TRUE
)
getTopFeatures(shapeGraph, "Connectivity", 0.1)

Create isovists at point and direction angle

Description

Create one or more isovists at particular points, given angle and field of view

Usage

isovist(boundaryMap, x, y, angle = NA, viewAngle = NA, verbose = FALSE)

Arguments

boundaryMap

A ShapeMap with lines designating the isovist boundaries
x

X coordinate of the origin points
y

Y coordinate of the origin points
angle

The angle (from the X axis) of the isovist look direction
viewAngle

The angle signifying the isovist's field of view
verbose

Optional. Show more information of the process.

Value

A ShapeMap with the isovist polygons

Examples

mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeMap <- as(sfMap[, vector()], "ShapeMap")
isovist(
  shapeMap,
  x = c(3.01, 1.3),
  y = c(6.70, 5.2),
  angle = 0.01,
  viewAngle = 3.14,
  FALSE
)

Create isovists using two points

Description

Create one or more isovists at particular points, given another point for direction and an angle for field of view

Usage

isovist2pts(boundaryMap, x, y, toX, toY, viewAngle, verbose = FALSE)

Arguments

boundaryMap

A ShapeMap with lines designating the isovist boundaries
x

X coordinate of the origin points
y

Y coordinate of the origin points
toX

X coordinate of the target points
toY

Y coordinate of the target points
viewAngle

The angle signifying the isovist's field of view
verbose

Optional. Show more information of the process.

Value

A ShapeMap with the isovist polygons

Examples

mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeMap <- as(sfMap[, vector()], "ShapeMap")
isovist2pts(
  shapeMap,
  x = c(3.01, 1.3),
  y = c(6.70, 5.2),
  toX = c(3.40, 1.1),
  toY = c(6.50, 5.6),
  viewAngle = 3.14,
  FALSE
)

Link map points/lines as if selecting them using points

Description

Link map points/lines as if selecting them using points

Usage

linkCoords(map, fromX, fromY, toX, toY, copyMap = TRUE)

Arguments

map

A sala map
fromX

X coordinate of the origin point
fromY

Y coordinate of the origin point
toX

X coordinate of the target point
toY

Y coordinate of the target point
copyMap

Optional. Copy the internal sala map

Value

A new map with linked points/lines

Link two Axial Lines (coordinates)

Description

Link two locations on an Axial ShapeGraph using the point coordinates

Usage

## S4 method for signature 'AxialShapeGraph'
linkCoords(map, fromX, fromY, toX, toY, copyMap = TRUE)

Arguments

map

An Axial ShapeGraph
fromX

X coordinate of the first link point
fromY

Y coordinate of the first link point
toX

X coordinate of the second link point
toY

Y coordinate of the second link point
copyMap

Optional. Copy the internal sala map

Value

A new Axial ShapeGraph with linked lines

Examples

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")
linkCoords(shapeGraph, 982.8, -1620.3, 1217.1, -1977.3)

Link two PointMap Cells (coordinates)

Description

Link two cells on a PointMap using the point coordinates

Usage

## S4 method for signature 'PointMap'
linkCoords(map, fromX, fromY, toX, toY, copyMap = TRUE)

Arguments

map

A PointMap
fromX

X coordinate of the first link point
fromY

Y coordinate of the first link point
toX

X coordinate of the second link point
toY

Y coordinate of the second link point
copyMap

Optional. Copy the internal sala map

Value

A new PointMap with linked points

Examples

mifFile <- system.file(
    "extdata", "testdata", "gallery",
    "gallery_lines.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  pointMap <- makeVGAPointMap(
    sfMap,
    gridSize = 0.04,
    fillX = 3.01,
    fillY = 6.7,
    maxVisibility = NA,
    boundaryGraph = FALSE,
    verbose = FALSE
  )
linkCoords(pointMap, 1.74, 6.7, 5.05, 5.24)

Link map points/lines using their refs

Description

Link map points/lines using their refs

Usage

linkRefs(map, fromRef, toRef, copyMap = TRUE)

Arguments

map

A sala map
fromRef

The ref of the origin element
toRef

The ref of the target element
copyMap

Optional. Copy the internal sala map

Value

A new map with linked points/lines

Link two Axial Lines (refs)

Description

Link two lines on an Axial ShapeGraph using their refs

Usage

## S4 method for signature 'AxialShapeGraph'
linkRefs(map, fromRef, toRef, copyMap = TRUE)

Arguments

map

An Axial ShapeGraph
fromRef

Ref of the first link line
toRef

Ref of the second link line
copyMap

Optional. Copy the internal sala map

Value

A new Axial ShapeGraph with linked lines

Examples

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")
linkRefs(shapeGraph, 0L, 9L)

Link two PointMap Cells (refs)

Description

Link two cells on an PointMap using their refs

Usage

## S4 method for signature 'PointMap'
linkRefs(map, fromRef, toRef, copyMap = TRUE)

Arguments

map

A PointMap
fromRef

Ref of the first link line
toRef

Ref of the second link line
copyMap

Optional. Copy the internal sala map

Value

A new PointMap with linked points

Examples

mifFile <- system.file(
    "extdata", "testdata", "gallery",
    "gallery_lines.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  pointMap <- makeVGAPointMap(
    sfMap,
    gridSize = 0.04,
    fillX = 3.01,
    fillY = 6.7,
    maxVisibility = NA,
    boundaryGraph = FALSE,
    verbose = FALSE
  )
pointMap <- linkRefs(pointMap, 1835056L, 7208971L)

Get map links

Description

Get map links

Usage

links(map)

Arguments

map

A sala map

Value

A matrix with the linked refs

Get the Axial ShapeGraph links

Description

Get the Axial ShapeGraph links

Usage

## S4 method for signature 'AxialShapeGraph'
links(map)

Arguments

map

An Axial ShapeGraph

Value

A matrix with the linked refs

Examples

# links of an axial map
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")
linkRefs(shapeGraph, 0L, 9L)
unlinkCoords(shapeGraph, 530923.0, 184041.0, 530956.0, 183887.0)
links(shapeGraph)

Get the PointMap links

Description

Get the PointMap links

Usage

## S4 method for signature 'PointMap'
links(map)

Arguments

map

A PointMap

Value

A matrix with the linked refs

Examples

mifFile <- system.file(
    "extdata", "testdata", "gallery",
    "gallery_lines.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  pointMap <- makeVGAPointMap(
    sfMap,
    gridSize = 0.04,
    fillX = 3.01,
    fillY = 6.7,
    maxVisibility = NA,
    boundaryGraph = FALSE,
    verbose = FALSE
  )
linkRefs(pointMap, 1835056L, 7208971L)
links(pointMap)

Create an All-line Map

Description

Create an All-line Map

Usage

makeAllLineMap(boundsMap, seedX, seedY, verbose = FALSE)

Arguments

boundsMap

The boundary ShapeMap to create the all-line map in
seedX

X coordinate of the seed (the point that initiates the process)
seedY

Y coordinate of the seed (the point that initiates the process)
verbose

Optional. Show more information of the process.

Value

An All-line Axial ShapeGraph

Examples

mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeMap <- as(sfMap[, vector()], "ShapeMap")
makeAllLineMap(
  shapeMap,
  seedX = 3.01,
  seedY = 6.7
)

Single Colour from depthmapX's Palettes

Description

Create a single colour from depthmapX's palettes.

Usage

makeDepthmapClassicColour(value, rangeMin = 0, rangeMax = 1)

makeAxmanesqueColour(value, rangeMin = 0, rangeMax = 1)

makePurpleOrangeColour(value, rangeMin = 0, rangeMax = 1)

makeBlueRedColour(value, rangeMin = 0, rangeMax = 1)

makeGreyScaleColour(value, rangeMin = 0, rangeMax = 1)

makeNiceHSBColour(value, rangeMin = 0, rangeMax = 1)

Arguments

value

Value within the min/max range to take
rangeMin

The min value of the range
rangeMax

The max value of the range

Value

Returns a single colour.

Examples

makeDepthmapClassicColour(0.2, 0, 1)
makeAxmanesqueColour(0.2, 0, 1)
makePurpleOrangeColour(0.2, 0, 1)
makeBlueRedColour(0.2, 0, 1)
makeGreyScaleColour(0.2, 0, 1)
makeNiceHSBColour(0.2, 0, 1)

Create a graph between visible cells in the PointMap

Description

Create a graph between visible cells in the PointMap

Usage

makeVGAGraph(
  pointMap,
  boundaryGraph = FALSE,
  maxVisibility = NA,
  copyMap = TRUE,
  verbose = FALSE
)

Arguments

pointMap

The input PointMap
boundaryGraph

Only create a graph on the boundary cells
maxVisibility

Limit how far two cells can be to be connected
copyMap

Optional. Copy the internal sala map
verbose

Optional. Show more information of the process.

Value

A new PointMap with a graph between points

Examples

mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeMap <- as(sfMap[, vector()], "ShapeMap")
lineStringMap <- as(sfMap, "sf")
mapRegion <- sf::st_bbox(lineStringMap)
pointMap <- createGrid(
  minX = mapRegion[["xmin"]],
  minY = mapRegion[["ymin"]],
  maxX = mapRegion[["xmax"]],
  maxY = mapRegion[["ymax"]],
  gridSize = 0.5
)
pointMap <- blockLines(
  pointMap = pointMap,
  lineStringMap = lineStringMap[vector()]
)
pointMap <- fillGrid(
  pointMap = pointMap,
  fillX = 3.01,
  fillY = 6.7
)
makeVGAGraph(
  pointMap = pointMap,
  boundaryGraph = FALSE,
  maxVisibility = NA
)

Create a PointMap grid, fill it and make the graph

Description

This is intended to be a single command to get from the lines to a PointMap ready for analysis

Usage

makeVGAPointMap(
  lineStringMap,
  gridSize,
  fillX,
  fillY,
  maxVisibility = NA,
  boundaryGraph = FALSE,
  verbose = FALSE
)

Arguments

lineStringMap

Map of lines, either a ShapeMap, or an sf lineString map
gridSize

Size of the cells
fillX

X coordinate of the fill points
fillY

Y coordinate of the fill points
maxVisibility

Limit how far two cells can be to be connected
boundaryGraph

Only create a graph on the boundary cells
verbose

Optional. Show more information of the process.

Value

A new PointMap

Examples

mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeMap <- as(sfMap[, vector()], "ShapeMap")
makeVGAPointMap(
  sfMap,
  gridSize = 0.5,
  fillX = 3.01,
  fillY = 6.7,
  maxVisibility = NA,
  boundaryGraph = FALSE,
  verbose = FALSE
)

Match points to lines

Description

Match points to their closest line. Matches (spatial-join) points to lines. Finds the point closest to a line. One point is attached to one line, thus if fewer points than lines are given then some lines will have no point attached.

Usage

matchPointsToLines(points, lines, getIndex = FALSE)

Arguments

points

Points to attach.
lines

Lines to attach to.
getIndex

Get the index returned and not the data.

Value

If getIndex is TRUE then the index of the points as they relate to the matching lines are given. If not, then the data from the points dataframe is returned.

Examples

segmentsMif <- system.file(
    "extdata", "testdata", "barnsbury",
    "barnsbury_small_segment_original.mif",
    package = "alcyon"
)
segmentsSf <- st_read(
    segmentsMif,
    geometry_column = 1L, quiet = TRUE
)
gateCountsMif <- system.file(
    "extdata", "testdata", "barnsbury",
    "barnsbury_ped_gatecounts.mif",
    package = "alcyon"
)
gateCountsSf <- st_read(
    gateCountsMif,
    geometry_column = 1L, quiet = TRUE
)
matchPointsToLines(gateCountsSf, segmentsSf)

Get map name

Description

Get map name

Usage

name(map)

Arguments

map

A sala map

Value

The name of the object as a string

Get the PointMap name

Description

Get the PointMap name

Usage

## S4 method for signature 'PointMap'
name(map)

Arguments

map

A PointMap

Value

The name of the PointMap as a string

Examples

mifFile <- system.file(
    "extdata", "testdata", "gallery",
    "gallery_lines.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  pointMap <- makeVGAPointMap(
    sfMap,
    gridSize = 0.04,
    fillX = 3.01,
    fillY = 6.7,
    maxVisibility = NA,
    boundaryGraph = FALSE,
    verbose = FALSE
  )
name(pointMap)

Get the ShapeMap name

Description

Get the ShapeMap name

Usage

## S4 method for signature 'ShapeMap'
name(map)

Arguments

map

A ShapeMap

Value

The name of the ShapeMap as a string

Examples

mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeMap <- as(sfMap[, vector()], "ShapeMap")
name(shapeMap)

One-to-all traversal

Description

Runs one-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

oneToAllTraverse(
  map,
  traversalType,
  fromX,
  fromY,
  quantizationWidth = NA,
  copyMap = TRUE,
  verbose = FALSE
)

Arguments

map

A PointMap, Axial ShapeGraph or Segment ShapeGraph
traversalType

The traversal type. See TraversalType
fromX

X coordinate of the point to start the traversal from
fromY

X coordinate of the point to start the traversal from
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
copyMap

Optional. Copy the internal sala map
verbose

Optional. Show more information of the process.

Value

Returns a list with:

  • completed: Whether the analysis completed

  • newAttributes: The new attributes that were created during the process

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
  )
oneToAllTraverse(
  pointMap,
  traversalType = TraversalType$Metric,
  fromX = 3.01,
  fromY = 6.7
)

# 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")
oneToAllTraverse(
  shapeGraph,
  traversalType = TraversalType$Topological,
  fromX = 1217.1,
  fromY = -1977.3
)

# 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")
oneToAllTraverse(
  shapeGraph,
  traversalType = TraversalType$Topological,
  fromX = 1217.1,
  fromY = -1977.3
)

One-to-one traversal

Description

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

  • PointMaps (Visibility Graph Analysis)

  • Segment ShapeGraphs (Segment analysis)

Usage

oneToOneTraverse(
  map,
  traversalType,
  fromX,
  fromY,
  toX,
  toY,
  quantizationWidth = NA,
  copyMap = TRUE,
  verbose = FALSE
)

Arguments

map

A PointMap or Segment ShapeGraph
traversalType

The traversal type. See TraversalType
fromX

X coordinate of the point(s) to start the traversal from
fromY

X coordinate of the point(s) to start the traversal from
toX

X coordinate of the point(s) to start the traversal from
toY

X coordinate of the point(s) to start the traversal from
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
copyMap

Optional. Copy the internal sala map
verbose

Optional. Show more information of the process.

Value

Returns a list with:

  • completed: Whether the analysis completed

  • newAttributes: The new attributes that were created during the process

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
  )
oneToOneTraverse(
  pointMap,
  traversalType = TraversalType$Metric,
  fromX = 7.52,
  fromY = 6.02,
  toX = 5.78,
  toY = 2.96
)

# 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")
oneToOneTraverse(
  shapeGraph,
  traversalType = TraversalType$Topological,
  fromX = 1217.1,
  fromY = -1977.3,
  toX = 1017.8,
  toY = -1699.3
)

Colour Palettes from depthmapX

Description

Create n contiguous colours taken from depthmapX.

Usage

depthmap.classic.colour(n, rangeMin = 0, rangeMax = 1)

depthmap.axmanesque.colour(n, rangeMin = 0, rangeMax = 1)

depthmap.purpleorange.colour(n, rangeMin = 0, rangeMax = 1)

depthmap.bluered.colour(n, rangeMin = 0, rangeMax = 1)

depthmap.grayscale.colour(n, rangeMin = 0, rangeMax = 1)

depthmap.nicehsb.colour(n, rangeMin = 0, rangeMax = 1)

Arguments

n

Number of colours to generate
rangeMin

The min value of the range
rangeMax

The max value of the range

Value

Returns a vector of colours.

Examples

depthmap.classic.colour(100, 0, 1)
depthmap.axmanesque.colour(100, 0, 1)
depthmap.purpleorange.colour(100, 0, 1)
depthmap.bluered.colour(100, 0, 1)
depthmap.grayscale.colour(100, 0, 1)
depthmap.nicehsb.colour(100, 0, 1)

plot a PointMap

Description

Calls a standard plot.stars, but flips the first argument around the x axis

Usage

## S3 method for class 'PointMap'
plot(x, ...)

Arguments

x

object of class PointMap
...

other parameters passed to stars[]

Subset PointMap objects

Description

Subsetting PointMap objects essentially passes the data to stars See stars_subset

Usage

## S3 method for class 'PointMap'
x[...]

## S3 replacement method for class 'PointMap'
x[...] <- value

Arguments

x

object of class PointMap passed to stars[]
...

other parameters passed to stars[] <-

value

value to be passed to stars[] <-

PointMap

Description

A representation of sala's PointMap in R. Holds onto a sala PointMap pointer and operates on that

Read MetaGraph

Description

Reads a metagraph into a bunch of ShapeMaps/ShapeGraphs/PointMaps

Usage

readMetaGraph(fileName)

Arguments

fileName

The metagraph file

Value

A list of ShapeMaps, ShapeGraphs and PointMaps

Examples

fileName <- system.file(
    "extdata", "testdata", "barnsbury", "barnsburySmall.graph",
    package = "alcyon"
)
readMetaGraph(fileName)

Reduce an All-line Map to two types of fewest-line maps

Description

Reduce an All-line Map to two types of fewest-line maps

Usage

reduceToFewest(allLineMap)

Arguments

allLineMap

An AllLineShapeGraph

Value

A list with two fewest-line axial ShapeGraphs

Examples

mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeMap <- as(sfMap[, vector()], "ShapeMap")
allLineMap <- makeAllLineMap(
  shapeMap,
  seedX = 3.01,
  seedY = 6.7
)
reduceToFewest(allLineMap)

Ref ID to index and vice-versa

Description

Converts a depthmapX "Ref" ID to the indices (x, y) of a cell, or the reverse

Usage

refIDtoIndex(refID)

indexToRefID(i, j)

Arguments

refID

The Ref ID
i

The x-axis index of the cell
j

The y-axis index of the cell

Value

A pair of indices (x, y) or a Ref ID

Examples

idx <- refIDtoIndex(852645)
# outputs:
#    i   j
# 1 13 677

idx <- indexToRefID(13, 667)
# outputs:
# 852645

Subset SegmentShapeGraph objects

Description

Subsetting SegmentShapeGraph objects essentially passes the data to sf. See sf

Usage

## S3 method for class 'SegmentShapeGraph'
x[...]

## S3 replacement method for class 'SegmentShapeGraph'
x[...] <- value

Arguments

x

object of class SegmentShapeGraph passed to stars[]
...

other parameters passed to stars[] <-

value

value to be passed to sf[] <-

Segment ShapeGraph

Description

A representation of sala's Segment ShapeGraph in R. Holds onto a sala Segment ShapeGraph pointer and operates on that

See Also

Other SegmentShapeGraph: as()

Conversion of shapegraph to graph data

Description

Creates data to be construct a graph, based on the connections and the x,y coordinates of the centroids of shapes in a shapegraph (axial, segment, convex). Specify weightColumn to assign weight to graph edges.

Usage

shapegraphToGraphData(shapeGraph, weightColumn = NA)

Arguments

shapeGraph

A ShapeGraph
weightColumn

Optional. The variable used to assign weight to graph edges

Details

If weightColumn is provided, edge connections weight is calculated by taking the average of the variable of the connected nodes.

Value

Returns a list with edges and vertices for constructing a graph.

Examples

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")
shapegraphToGraphData(shapeGraph)

Subset ShapeMap objects

Description

Subsetting ShapeMap objects essentially passes the data to sf. See sf

Usage

## S3 method for class 'ShapeMap'
x[...]

## S3 replacement method for class 'ShapeMap'
x[...] <- value

Arguments

x

object of class ShapeMap passed to sf[]
...

other parameters passed to sf[] <-

value

value to be passed to sf[] <-

ShapeMap class

Description

A representation of sala's ShapeMap in R. Holds onto a sala ShapeMap pointer and operates on that

See Also

Other ShapeMap: as()

ShapeMap to sf Polygon map

Description

Convert a ShapeMap to an sf Polygon map

Usage

shapeMapToPolygonSf(shapeMap)

Arguments

shapeMap

A ShapeMap

Value

A new sf Polygon map

Examples

mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeMap <- as(sfMap[, vector()], "ShapeMap")
isovistMap <- isovist(
  shapeMap,
  x = c(3.01, 1.3),
  y = c(6.70, 5.2),
  angle = 0.01,
  viewAngle = 3.14,
  FALSE
)
shapeMapToPolygonSf(isovistMap)

Traversal types

Description

These are meant to be used to indicate what kind of analysis is meant to be carried out.

Usage

TraversalType

Format

An object of class list of length 4.

Value

A list of numbers representing each particular analysis type

Examples

TraversalType$Angular
TraversalType$Topological
TraversalType$Metric

Unlink map lines at their crossing point

Description

Unlink map lines at their crossing point

Usage

unlinkAtCrossPoint(map, x, y, copyMap = TRUE)

Arguments

map

A sala map
x

X coordinate of the crossing point
y

Y coordinate of the crossing point
copyMap

Optional. Copy the internal sala map

Value

A new map with linked lines

Unlink two Axial Lines (crosspoint)

Description

Unlink two crossing lines on an Axial ShapeGraph at the crossing point

Usage

## S4 method for signature 'AxialShapeGraph'
unlinkAtCrossPoint(map, x, y, copyMap = TRUE)

Arguments

map

An Axial ShapeGraph
x

X coordinate of the unlink crossing point
y

Y coordinate of the unlink crossing point
copyMap

Optional. Copy the internal sala map

Value

A new Axial ShapeGraph with unlinked lines

Examples

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")
unlinkAtCrossPoint(shapeGraph, 530925.0, 184119.0)

Unlink map points/lines as if selecting them using points

Description

Unlink map points/lines as if selecting them using points

Usage

unlinkCoords(map, fromX, fromY, toX, toY, copyMap = TRUE)

Arguments

map

A sala map
fromX

X coordinate of the origin point
fromY

Y coordinate of the origin point
toX

X coordinate of the target point
toY

Y coordinate of the target point
copyMap

Optional. Copy the internal sala map

Value

A new map with unlinked points/lines

Unlink two Axial Lines (coordinates)

Description

Unlink two locations on an Axial ShapeGraph using the point coordinates

Usage

## S4 method for signature 'AxialShapeGraph'
unlinkCoords(map, fromX, fromY, toX, toY, copyMap = TRUE)

Arguments

map

An Axial ShapeGraph
fromX

X coordinate of the first unlink point
fromY

Y coordinate of the first unlink point
toX

X coordinate of the second unlink point
toY

Y coordinate of the second unlink point
copyMap

Optional. Copy the internal sala map

Value

A new Axial ShapeGraph with unlinked lines

Examples

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")
unlinkCoords(shapeGraph, 982.8, -1620.3, 1080.4, -1873.5)

Unlink two PointMap Cells (coordinates)

Description

Unlink two cells on a PointMap using the point coordinates

Usage

## S4 method for signature 'PointMap'
unlinkCoords(map, fromX, fromY, toX, toY, copyMap = TRUE)

Arguments

map

A PointMap
fromX

X coordinate of the first unlink point
fromY

Y coordinate of the first unlink point
toX

X coordinate of the second unlink point
toY

Y coordinate of the second unlink point
copyMap

Optional. Copy the internal sala map

Value

A new PointMap with unlinked points

Examples

mifFile <- system.file(
    "extdata", "testdata", "gallery",
    "gallery_lines.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  pointMap <- makeVGAPointMap(
    sfMap,
    gridSize = 0.04,
    fillX = 3.01,
    fillY = 6.7,
    maxVisibility = NA,
    boundaryGraph = FALSE,
    verbose = FALSE
  )
pointMap <- linkCoords(pointMap, 1.74, 6.7, 5.05, 5.24)
pointMap <- unlinkCoords(pointMap, 1.74, 6.7, 5.05, 5.24)

Unlink map points/lines using their refs

Description

Unlink map points/lines using their refs

Usage

unlinkRefs(map, fromRef, toRef, copyMap = TRUE)

Arguments

map

A sala map
fromRef

The ref of the origin element
toRef

The ref of the target element
copyMap

Optional. Copy the internal sala map

Value

A new map with unlinked points/lines

Unlink two Axial Lines (refs)

Description

Unlink two lines on an Axial ShapeGraph using their refs

Usage

## S4 method for signature 'AxialShapeGraph'
unlinkRefs(map, fromRef, toRef, copyMap = TRUE)

Arguments

map

An Axial ShapeGraph
fromRef

Ref of the first unlink line
toRef

Ref of the second unlink line
copyMap

Optional. Copy the internal sala map

Value

A new Axial ShapeGraph with unlinked lines

Examples

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")
unlinkRefs(shapeGraph, 12L, 34L)

Unlink two PointMap Cells (refs)

Description

Unlink two cells on an PointMap using their refs

Usage

## S4 method for signature 'PointMap'
unlinkRefs(map, fromRef, toRef, copyMap = TRUE)

Arguments

map

A PointMap
fromRef

Ref of the first unlink line
toRef

Ref of the second unlink line
copyMap

Optional. Copy the internal sala map

Value

A new PointMap with unlinked points

Examples

mifFile <- system.file(
    "extdata", "testdata", "gallery",
    "gallery_lines.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  pointMap <- makeVGAPointMap(
    sfMap,
    gridSize = 0.04,
    fillX = 3.01,
    fillY = 6.7,
    maxVisibility = NA,
    boundaryGraph = FALSE,
    verbose = FALSE
  )
pointMap <- linkRefs(pointMap, 1835056L, 7208971L)
pointMap <- unlinkRefs(pointMap, 1835056L, 7208971L)

Unmake the graph in a PointMap

Description

Unmake the graph in a PointMap

Usage

unmakeVGAGraph(pointMap, removeLinks = FALSE, copyMap = TRUE, verbose = FALSE)

Arguments

pointMap

The input PointMap
removeLinks

Also remove the links
copyMap

Optional. Copy the internal sala map
verbose

Optional. Show more information of the process.

Value

A new PointMap without the points graph

Examples

mifFile <- system.file(
    "extdata", "testdata", "simple",
    "simple_interior.mif",
    package = "alcyon"
  )
  sfMap <- st_read(mifFile,
    geometry_column = 1L, quiet = TRUE
  )
  shapeMap <- as(sfMap[, vector()], "ShapeMap")
pointMap <- makeVGAPointMap(
  sfMap,
  gridSize = 0.5,
  fillX = 3.01,
  fillY = 6.7,
  maxVisibility = NA,
  boundaryGraph = FALSE,
  verbose = FALSE
)
unmakeVGAGraph(
  pointMap = pointMap,
  removeLinks = FALSE
)

Visibility Graph Analysis - isovist metrics

Description

Runs axial analysis to get the local metrics Control and Controllability

Usage

vgaIsovist(pointMap, boundaryMap, copyMap = TRUE)

Arguments

pointMap

A PointMap
boundaryMap

A ShapeMap of lines
copyMap

Optional. Copy the internal sala map

Value

A new PointMap with the results included

Examples

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
  )
boundaryMap <- as(sfMap[, c()], "ShapeMap")
vgaIsovist(pointMap, boundaryMap)

VGA Local Analysis algorithms.

Description

Different algorithms for calculating the VGA Local metrics (Control, Controllability, Clustering Coefficient).

  • VGALocalAlgorithm$None

  • VGALocalAlgorithm$Standard

  • VGALocalAlgorithm$AdjacencyMatrix

Usage

VGALocalAlgorithm

Format

An object of class list of length 3.

Value

A list of numbers representing each algorithm

Examples

VGALocalAlgorithm$Angular
VGALocalAlgorithm$Topological
VGALocalAlgorithm$Metric

Visibility Graph Analysis - Through Vision

Description

Runs Visibility Graph Analysis to get the Through Vision metric

Usage

vgaThroughVision(pointMap, copyMap = TRUE)

Arguments

pointMap

A PointMap
copyMap

Optional. Copy the internal sala map

Value

A new PointMap with the results included

Examples

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
  )
vgaThroughVision(pointMap)

Visibility Graph Analysis - Visual local metrics

Description

Runs Visibility Graph Analysis to get visual local metrics

Usage

vgaVisualLocal(
  pointMap,
  nthreads = 1L,
  algorithm = VGALocalAlgorithm$Standard,
  copyMap = TRUE,
  gatesOnly = FALSE,
  progress = FALSE
)

Arguments

pointMap

A PointMap
nthreads

Optional. Number of threads to use (defaults to 1)
algorithm

Optional. The algorithm to use. See ?VGALocalAlgorithm
copyMap

Optional. Copy the internal sala map
gatesOnly

Optional. Only keep the values at specific gates
progress

Optional. Enable progress display

Value

A new PointMap with the results included

Examples

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
  )
vgaVisualLocal(pointMap, FALSE)