Package 'pavement' reference manual

Title:	Analyzing Spatial Events on Roadways
Description:	Pavement is a package designed to analyze spatial events occurring on roadways. It provides a comprehensive toolkit for working with spatial data, empowering users to understand patterns and trends in road-related phenomena.
Authors:	Keisuke ANDO [aut, cre] , Takeshi UCHITANE [ths], Naoto MUKAI [ths], Kazunori IWATA [ths], Nobuhiro ITO [ths], Yong JIANG [ths]
Maintainer:	Keisuke ANDO <[email protected]>
License:	MIT + file LICENSE
Version:	0.0.1
Built:	2025-03-11 06:02:41 UTC
Source:	https://github.com/NONONOexe/pavement

Compute the Epanechnikov function

Description

The Epanechnikov function is one of the quadratic kernels used in kernel density estimation. It is defined as follows:

$K(x) = \frac{3}{4}(1 - x^2) \quad \text{if} \quad |x| \leq 1\text{.}$

Usage

compute_epanechnikov(x)
compute_epanechnikov(x)

Arguments

`x`	A numeric vector.

Value

A numeric vector of weights of the kernel for each input points.

Examples

x <- seq(-3, 3, 0.1)
y <- compute_epanechnikov(x)
plot(x, y, xlim = c(-3, 3), ylim = c(0, 1), type = "l")
x <- seq(-3, 3, 0.1)
y <- compute_epanechnikov(x)
plot(x, y, xlim = c(-3, 3), ylim = c(0, 1), type = "l")

Compute the Gaussian function

Description

The Gaussian function is a bell-shaped function defined as follows:

$K(x) = \frac{1}{\sqrt{2\pi\sigma^2}} \exp\left( -\frac{x^2}{2\sigma^2} \right)\text{.}$

Usage

compute_gaussian(x, sigma = 1)
compute_gaussian(x, sigma = 1)

Arguments

`x`	A numric vector.
`sigma`	The standard deviation of the Gaussian function.

Value

A numeric vector of weights of the kernel for each input points.

Examples

x <- seq(-3, 3, 0.1)
y <- compute_gaussian(x, sigma = 1)
plot(x, y, xlim = c(-3, 3), ylim = c(0, 1), type = "l")
x <- seq(-3, 3, 0.1)
y <- compute_gaussian(x, sigma = 1)
plot(x, y, xlim = c(-3, 3), ylim = c(0, 1), type = "l")

Convert a bounding box to coordinates or a polygon

Description

This function converts a bounding box to either coordinates or a polygon.

Usage

convert_bbox(bbox, output = c("coordinates", "polygon"), crs = NULL)

convert_bbox_to_coordinates(bbox)

convert_bbox_to_polygon(bbox, crs = NULL)
convert_bbox(bbox, output = c("coordinates", "polygon"), crs = NULL)

convert_bbox_to_coordinates(bbox)

convert_bbox_to_polygon(bbox, crs = NULL)

Arguments

`bbox`	A numeric matrix with two columns and two rows. `bbox` represents the minimum and maximum coordinates. The bounding box can be created using the `create_bbox` function.
`output`	A string specifying the output type. Either "coordinates" or "polygon".
`crs`	A string specifying the coordinate reference system. This is only used when converting to a polygon.

Value

A coordinates object or a sfc polygon object.

Examples

bbox <- create_bbox(center_lon = 136.9024,
                    center_lat =  35.1649,
                    width      = 0.10,
                    height     = 0.05)
convert_bbox_to_coordinates(bbox)
convert_bbox_to_polygon(bbox, crs = 4326)
bbox <- create_bbox(center_lon = 136.9024,
                    center_lat =  35.1649,
                    width      = 0.10,
                    height     = 0.05)
convert_bbox_to_coordinates(bbox)
convert_bbox_to_polygon(bbox, crs = 4326)

Convolute segmented road network

Description

This function convolves a segmented network using a specified kernel function, typically for traffic modeling or network analysis. It computes weights densities based on the distance between links in the network and the number of events assigned to each link. Optionally, it can adjust for branching in the network.

Usage

convolute_segmented_network(
  segmented_network,
  kernel = compute_epanechnikov,
  bandwidth = 3,
  use_esd = TRUE,
  correct_boundary_effects = TRUE,
  ...
)
convolute_segmented_network(
  segmented_network,
  kernel = compute_epanechnikov,
  bandwidth = 3,
  use_esd = TRUE,
  correct_boundary_effects = TRUE,
  ...
)

Arguments

`segmented_network`	A `segmented_network` object assigned with events.
`kernel`	A kernel function to use for convolution (default is Epanechnikov kernel).
`bandwidth`	Numeric value representing the bandwidth for the kernel function (default is 3).
`use_esd`	If `TRUE`, considers branching in the kernel using the Equal Split Discontinous kernel (ESD). ESD follows the method described in Okabe et al., accounting for road intersections and ensuring that kernel weights are correctly distributed across accross branches (default is `TRUE`).
`correct_boundary_effects`	If `TRUE`, corrects for boundary effects by normalizing the kernel weights to account for kernel values outside the network (default is `TRUE`).
`...`	Additional arguments passed to the kernel function.

Value

The segmented network with updated link densities.

References

Okabe, A., Satoh, T., & Sugihara, K. (2009). A kernel density estimation method for networks, its computational method and a GIS-based tool. International Journal of Geographical Information Science, 23(1), 7-32. doi:10.1080/13658810802475491

Examples

# Create a road network
road_network <- create_road_network(sample_roads)

# Assign sample accidents data
road_network <- set_events(road_network, sample_accidents)

# Segment the road network
segmented_network <- create_segmented_network(
  road_network,
  segment_length = 0.5
)

# Check the segmented road network after assigning events
segmented_network

# Apply the convilution to calculate link densities using
# the kernel function
convoluted_network <- convolute_segmented_network(segmented_network)

# Check the convoluted network with the computed densities
convoluted_network

# Plot the convoluted network showing the density distribution
plot(convoluted_network, mode = "density")
# Create a road network
road_network <- create_road_network(sample_roads)

# Assign sample accidents data
road_network <- set_events(road_network, sample_accidents)

# Segment the road network
segmented_network <- create_segmented_network(
  road_network,
  segment_length = 0.5
)

# Check the segmented road network after assigning events
segmented_network

# Apply the convilution to calculate link densities using
# the kernel function
convoluted_network <- convolute_segmented_network(segmented_network)

# Check the convoluted network with the computed densities
convoluted_network

# Plot the convoluted network showing the density distribution
plot(convoluted_network, mode = "density")

Create a bounding box

Description

This function creates a bounding box from either cardinal coordinates (north, south, east and west) or center coordinates and dimensions (center longitude and latitude, and size of width and height).

Usage

create_bbox(
  north = NULL,
  south = NULL,
  east = NULL,
  west = NULL,
  center_lon = NULL,
  center_lat = NULL,
  width = NULL,
  height = NULL
)
create_bbox(
  north = NULL,
  south = NULL,
  east = NULL,
  west = NULL,
  center_lon = NULL,
  center_lat = NULL,
  width = NULL,
  height = NULL
)

Arguments

`north`	The northernmost latitude.
`south`	The southernmost latitude.
`east`	The easternmost longitude.
`west`	The westernmost longitude.
`center_lon`	The center longitude.
`center_lat`	The center latitude.
`width`	The width of the bounding box.
`height`	The height of the bounding box.

Value

A 2x2 matrix representing the bounding box.

Examples

# Create a bounding box from cardinal coordinates
create_bbox(
  north =  35.1899,
  south =  35.1399,
  east  = 136.9524,
  west  = 136.8524
)

# Create a bounding box from center coordinates and dimensions
create_bbox(
  center_lon = 136.9024,
  center_lat =  35.1649,
  width      = 0.10,
  height     = 0.05
)
# Create a bounding box from cardinal coordinates
create_bbox(
  north =  35.1899,
  south =  35.1399,
  east  = 136.9524,
  west  = 136.8524
)

# Create a bounding box from center coordinates and dimensions
create_bbox(
  center_lon = 136.9024,
  center_lat =  35.1649,
  width      = 0.10,
  height     = 0.05
)

Create a collection of coordinates.

Description

This function creates a collection of coordinates from a sequence x and y coordinates.

Usage

create_coordinates(...)
create_coordinates(...)

Arguments

...

A sequence of x and y coordinates.

Value

A coordinates object which is a matrix with x and y columns.

Examples

# Create a `coordinates` object from a sequence of x and y coordinates
create_coordinates(1, 2, 3, 4)

# Create a `coordinates` object from an with a vector of x and y
# coordinates
create_coordinates(c(1, 2, 3, 4))
# Create a `coordinates` object from a sequence of x and y coordinates
create_coordinates(1, 2, 3, 4)

# Create a `coordinates` object from an with a vector of x and y
# coordinates
create_coordinates(c(1, 2, 3, 4))

Create a graph from nodes and links

Description

This function creates a graph object from a set of nodes and links.

Usage

create_graph(nodes, links, directed = FALSE)
create_graph(nodes, links, directed = FALSE)

Arguments

`nodes`	A `sf` object representing nodes.
`links`	A `sf` object representing links between nodes.
`directed`	A logical indicating whether the graph is directed.

Value

A igraph object.

Examples

# Create nodes and links
nodes <- extract_road_network_nodes(sample_roads)
links <- extract_road_network_links(sample_roads, nodes)

# Create the graph
graph <- create_graph(nodes, links)
graph

# Plot the graph
plot(graph)
# Create nodes and links
nodes <- extract_road_network_nodes(sample_roads)
links <- extract_road_network_links(sample_roads, nodes)

# Create the graph
graph <- create_graph(nodes, links)
graph

# Plot the graph
plot(graph)

Create a line graph from a network

Description

This function creates a line graph where nodes represent the midpoints of links in the input network.

Usage

create_line_graph(network)
create_line_graph(network)

Arguments

network

A road_network or segmented_network object.

Value

A igraph object representing the midpoint graph.

Examples

# Create a road network
network <- create_road_network(sample_roads)

# Plot the road network
plot(network$graph)

# Create a midpoint graph from a road network
graph <- create_line_graph(network)

# Plot the midpoint graph
plot(graph)
# Create a road network
network <- create_road_network(sample_roads)

# Plot the road network
plot(network$graph)

# Create a midpoint graph from a road network
graph <- create_line_graph(network)

# Plot the midpoint graph
plot(graph)

Create a linestring geometry

Description

This function creates a simple feature linestring object from a series of x, y coordinates.

Usage

create_linestring(...)

## S3 method for class 'numeric'
create_linestring(..., crs = NULL)

## S3 method for class 'coordinates'
create_linestring(coordinates, crs = NULL, ...)
create_linestring(...)

## S3 method for class 'numeric'
create_linestring(..., crs = NULL)

## S3 method for class 'coordinates'
create_linestring(coordinates, crs = NULL, ...)

Arguments

`...`	A series of x, y coordinates.
`crs`	The coordinate reference system.
`coordinates`	A `coordinates` object.

Value

A simple feature linestring object.

Examples

# Create a linestring from individual coordinates
linestring_1 <- create_linestring(0, 1, 1, 0, 2, 1)
linestring_1
plot(linestring_1)

# Create a linestring from a numeric vector
linestring_2 <- create_linestring(
  c(0, 1, 1, 1, 1, 0, 0, 0, 0, 0.5, 1, 0.5)
)
linestring_2
plot(linestring_2)
# Create a linestring from individual coordinates
linestring_1 <- create_linestring(0, 1, 1, 0, 2, 1)
linestring_1
plot(linestring_1)

# Create a linestring from a numeric vector
linestring_2 <- create_linestring(
  c(0, 1, 1, 1, 1, 0, 0, 0, 0, 0.5, 1, 0.5)
)
linestring_2
plot(linestring_2)

Create points geometry

Description

This function creates a simple feature collection of points from a series of x, y coordinates.

Usage

create_points(...)

## S3 method for class 'numeric'
create_points(..., crs = NULL)

## S3 method for class 'coordinates'
create_points(coordinates, crs = NULL, ...)
create_points(...)

## S3 method for class 'numeric'
create_points(..., crs = NULL)

## S3 method for class 'coordinates'
create_points(coordinates, crs = NULL, ...)

Arguments

`...`	A series of x, y coordinates.
`crs`	The coordinate reference system.
`coordinates`	A `coordinates` object.

Value

A simple feature points object.

Examples

# Create a points from individual coordinates
points_1 <- create_points(0, 1, 1, 0, 2, 1)
points_1
plot(points_1)

# Create a linestring from a numeric vector
points_2 <- create_points(
  c(0, 1, 1, 1, 1, 0, 0, 0, 0, 0.5, 1, 0.5)
)
points_2
plot(points_2)
# Create a points from individual coordinates
points_1 <- create_points(0, 1, 1, 0, 2, 1)
points_1
plot(points_1)

# Create a linestring from a numeric vector
points_2 <- create_points(
  c(0, 1, 1, 1, 1, 0, 0, 0, 0, 0.5, 1, 0.5)
)
points_2
plot(points_2)

Create a polygon geometry

Description

This function creates a polygon from a bounding box or a series of x, y coordinates.

Usage

create_polygon(...)

## S3 method for class 'numeric'
create_polygon(..., crs = NULL)

## S3 method for class 'coordinates'
create_polygon(coordinates, crs = NULL, ...)
create_polygon(...)

## S3 method for class 'numeric'
create_polygon(..., crs = NULL)

## S3 method for class 'coordinates'
create_polygon(coordinates, crs = NULL, ...)

Arguments

`...`	A series of x, y coordinates.
`crs`	The coordinate reference system.
`coordinates`	A `coordinates` object.

Value

A polygon object.

Examples

polygon <- create_polygon(
  136.9009, 35.16377,
  136.9159, 35.16377,
  136.9159, 35.17377,
  136.9009, 35.17377,
  crs = 4326
)
polygon <- create_polygon(
  136.9009, 35.16377,
  136.9159, 35.16377,
  136.9159, 35.17377,
  136.9009, 35.17377,
  crs = 4326
)

Decompose a linestring into a list of line segments

Description

This function decomposes a linestring into a list of line segments, where each segment is a linestring connecting two consecutive points of the input linestring.

Usage

decompose_linestring(linestring)
decompose_linestring(linestring)

Arguments

linestring

A linestring object.

Value

A list of linestring objects, each representing a segment of the input linestring.

Examples

# Create a linestring object
linestring <- create_linestring(0, -1, 0, 1, 2, 1, 2, 0, 0, 0)
plot(linestring)

# Decompose the linestring into line segments
segments <- decompose_linestring(linestring)
plot(segments, col = c("#E69F00", "#56B4E9", "#009E73", "#F0E442"))
# Create a linestring object
linestring <- create_linestring(0, -1, 0, 1, 2, 1, 2, 0, 0, 0)
plot(linestring)

# Decompose the linestring into line segments
segments <- decompose_linestring(linestring)
plot(segments, col = c("#E69F00", "#56B4E9", "#009E73", "#F0E442"))

Create durations

Description

This function creates a data frame of durations.

Usage

create_durations(duration_length, ...)
create_durations(duration_length, ...)

Arguments

`duration_length`	The length of each duration.
`...`	Additional arguments passed to or from other methods.

Value

A durations object.

Examples

# Create durations of 1 hour
create_durations("1 hour")

# Create durations of 30 minutes
create_durations("30 minutes")
# Create durations of 1 hour
create_durations("1 hour")

# Create durations of 30 minutes
create_durations("30 minutes")

Extract road endpoints

Description

This function extracts the endpoints of a set of roads. It identifies and counts the roads that intersect at each endpoint.

Usage

extract_road_endpoints(roads)
extract_road_endpoints(roads)

Arguments

roads

A linestring object representing roads. It should be have a column named road_id.

Value

A points object representing road endpoints. Each endpoint has the following columns:

parent_road: A list of road IDs that intersect at the endpoint.
num_overlaps: The number of roads that intersect at the endpoint.

Extract road intersections

Description

This function identifies and extracts intersections between roads. It considers only intersections where multiple roads on the same layer.

Usage

extract_road_intersections(roads)
extract_road_intersections(roads)

Arguments

roads

A linestring object representing roads. It should be have a column named layer and a column named road_id.

Value

A data frame with the following columns:

parent_road: A list of road IDs that intersect at the intersection.
num_overlaps: The number of roads that intersect at the intersection.

Examples

# Extract road intersections
intersections <- extract_road_intersections(sample_roads)
intersections

# Plot the intersections
plot(sample_roads$geometry)
plot(intersections$geometry, pch = 16, col = "#E69F00", add = TRUE)
# Extract road intersections
intersections <- extract_road_intersections(sample_roads)
intersections

# Plot the intersections
plot(sample_roads$geometry)
plot(intersections$geometry, pch = 16, col = "#E69F00", add = TRUE)

Extract road network links

Description

This function extracts the road network links from a set of road geometries. It splits the road geometries at the nodes and creates a new sf object representing the road network links.

Usage

extract_road_network_links(roads, nodes)
extract_road_network_links(roads, nodes)

Arguments

`roads`	A linestring object representing the roads.
`nodes`	A point object representing the road network nodes.

Value

A linestring object representing the road network links.

Extract road network nodes

Description

This function extracts nodes from roads represented as linestring objects downloaded from OpenStreetMap. Nodes are defined as intersections between roads and endpoints of road segments.

Usage

extract_road_network_nodes(roads)
extract_road_network_nodes(roads)

Arguments

roads

A linestring object representing roads.

Value

A points object representing road network nodes.

Extract segmented network links from a road network

Description

This function extracts the segmented network links from a road network based on a specified set of segmented network nodes. It splits the linestrings of the road network links at the points of the segmented network nodes to create the segmented network links.

Usage

extract_segmented_network_links(
  road_network,
  segmented_network_nodes,
  tolerance = 1e-05
)
extract_segmented_network_links(
  road_network,
  segmented_network_nodes,
  tolerance = 1e-05
)

Arguments

`road_network`	A `road_network` object created with `create_road_network()`
`segmented_network_nodes`	A data frame representing the segmented network nodes.
`tolerance`	A numeric value representing the maximum distance allowed between a linestring of a road link and a point of a segmented network node. If the distance exceeds this value, the point will not be used to split the linestring.

Value

A data frame representing the segmented network links.

Examples

# Create a road network
road_network <- create_road_network(sample_roads)

# Extract segmented network nodes by length of 1
segmented_network_nodes <- extract_segmented_network_nodes(road_network, 1)

# Extract segmented network links
segmented_network_links <- extract_segmented_network_links(
  road_network,
  segmented_network_nodes
)
segmented_network_links

# Plot the segmented network nodes and links
plot(segmented_network_links$geometry, col = "#E69F00")
plot(segmented_network_nodes$geometry, pch = 16, add = TRUE)
# Create a road network
road_network <- create_road_network(sample_roads)

# Extract segmented network nodes by length of 1
segmented_network_nodes <- extract_segmented_network_nodes(road_network, 1)

# Extract segmented network links
segmented_network_links <- extract_segmented_network_links(
  road_network,
  segmented_network_nodes
)
segmented_network_links

# Plot the segmented network nodes and links
plot(segmented_network_links$geometry, col = "#E69F00")
plot(segmented_network_nodes$geometry, pch = 16, add = TRUE)

Extract nodes of segmented network from a road network

Description

This function extracts nodes at regular intervals along each link in a road network

Usage

extract_segmented_network_nodes(road_network, segment_length)
extract_segmented_network_nodes(road_network, segment_length)

Arguments

`road_network`	A `road_network` object created with `create_network()`.
`segment_length`	The length of each segment to sample along the links.

Value

An sf object with the sampled points.

Examples

# Create a road network
road_network <- create_road_network(sample_roads)

# Extract nodes with a segment length of 1
segmented_network_nodes <- extract_segmented_network_nodes(road_network, 1)
segmented_network_nodes

# Plot the segmented network nodes
plot(road_network)
plot(segmented_network_nodes$geometry, add = TRUE, pch = 16, col = "#E69F00")
# Create a road network
road_network <- create_road_network(sample_roads)

# Extract nodes with a segment length of 1
segmented_network_nodes <- extract_segmented_network_nodes(road_network, 1)
segmented_network_nodes

# Plot the segmented network nodes
plot(road_network)
plot(segmented_network_nodes$geometry, add = TRUE, pch = 16, col = "#E69F00")

Fetch road data from OpenStreetMap

Description

fetch_roads() fetches road data from OpenStreetMap. It retrieves roads within a specified bounding box or within an area defined by a center point and a radius. Additionally, roads can be cropped to fit within the specified boundaries.

Usage

fetch_roads(x, ...)

## S3 method for class 'matrix'
fetch_roads(x, crop = FALSE, ...)

## S3 method for class 'sfc_POINT'
fetch_roads(x, radius = 15, crop = FALSE, circle_crop = FALSE, ...)

## S3 method for class 'POINT'
fetch_roads(x, radius = 15, crop = FALSE, circle_crop = FALSE, ...)

## S3 method for class 'numeric'
fetch_roads(x, y, radius = 15, crop = FALSE, circle_crop = FALSE, ...)

## S3 method for class 'character'
fetch_roads(x, crop = FALSE, circle_crop = FALSE, ...)
fetch_roads(x, ...)

## S3 method for class 'matrix'
fetch_roads(x, crop = FALSE, ...)

## S3 method for class 'sfc_POINT'
fetch_roads(x, radius = 15, crop = FALSE, circle_crop = FALSE, ...)

## S3 method for class 'POINT'
fetch_roads(x, radius = 15, crop = FALSE, circle_crop = FALSE, ...)

## S3 method for class 'numeric'
fetch_roads(x, y, radius = 15, crop = FALSE, circle_crop = FALSE, ...)

## S3 method for class 'character'
fetch_roads(x, crop = FALSE, circle_crop = FALSE, ...)

Arguments

`x`	An object defining the area or location of interest. This can be: A `matrix` representing a bounding box. An `sfc_POINT` or `POINT` object representing a central point. Numeric values representing longitude (`x`) and latitude (`y`). A character string containing a pre-defined Overpass query.
`...`	Additional arguments passed to the method.
`crop`	A logical value indicating whether to crop road data to the specified area (default: `FALSE`).
`radius`	Numeric value representing the search radius in meters (default: `15`).
`circle_crop`	A logical value indicating whether to crop roads within a circular area instead of a bounding box (default: `FALSE`). This is only effective if `crop = TRUE`.
`y`	Numeric value representing latitude (required if `x` is numeric and represents longitude).

Value

An sf object of class LINESTRING, containing road data with the followings columns:

id: Unique road identifier
highway: Road classification (e.g. "residential", "primary")
name: Road name
layer: Layer information for roads at different elevations
oneway: Logical indicating whether the road is one-way
osm_id: OpenStreetMap unique identifier

Examples

## Not run: 
# Download road data
bbox <- create_bbox(
  north =  35.17377,
  south =  35.16377,
  east  = 136.91590,
  west  = 136.90090
)
roads <- fetch_roads(bbox)

# Plot the roads
plot(roads$geometry)

## End(Not run)
## Not run: 
# Download road data
bbox <- create_bbox(
  north =  35.17377,
  south =  35.16377,
  east  = 136.91590,
  west  = 136.90090
)
roads <- fetch_roads(bbox)

# Plot the roads
plot(roads$geometry)

## End(Not run)

Filter and cast geometries

Description

This function filters a given geometries by specific type and casts it to the specified type.

Usage

filter_and_cast_geometries(
  geometries,
  geometry_type = c("POINT", "LINESTRING", "POLYGON")
)

get_points(geometries)

get_linestrings(geometries)

get_polygons(geometries)
filter_and_cast_geometries(
  geometries,
  geometry_type = c("POINT", "LINESTRING", "POLYGON")
)

get_points(geometries)

get_linestrings(geometries)

get_polygons(geometries)

Arguments

`geometries`	A `sf` object representing geometries.
`geometry_type`	The type of geometry to filter and cast to. Must be one of "POINT", "LINESTRING", or "POLYGON".

Value

A sf object containing only the specified type of geometry.

Examples

plot(1, type = "n", xlab = "", ylab = "", axes = FALSE, xlim = c(0, 12), ylim = c(0, 10))
text(0, c(2, 6), c("Single", "Multiple"), srt = 90, cex = 1)
text(c(2, 6, 10), 8, c("Point", "Linestring", "Polygon"), cex = 1)

geometries <- sf::st_sf(geometry = c(
  # POINT
  create_points(2, 2),
  # LINESTRING
  create_linestring(5, 1, 7, 3),
  # POLYGON
  create_polygon(9, 1, 9, 3, 11, 3, 11, 1),
  # MULTIPOINT
  sf::st_union(create_points(1, 7, 2, 6, 3, 5)),
  # MULTILINESTRING
  sf::st_union(
    create_linestring(5, 6, 6, 7),
    create_linestring(6, 5, 7, 6)
  ),
  # MULTIPOLYGON
  sf::st_union(
    create_polygon(9, 7, 10, 7, 10, 6, 9, 6),
    create_polygon(10, 5, 11, 6, 11, 5)
  )
))
plot(geometries, pch = 16, lwd = 2, add = TRUE)

# Get points from geometries
plot(get_points(geometries), pch = 16)

# Get linestrings from geometries
plot(get_linestrings(geometries), lwd = 2)

# Get polygons from geometries
plot(get_polygons(geometries), lwd = 2)
plot(1, type = "n", xlab = "", ylab = "", axes = FALSE, xlim = c(0, 12), ylim = c(0, 10))
text(0, c(2, 6), c("Single", "Multiple"), srt = 90, cex = 1)
text(c(2, 6, 10), 8, c("Point", "Linestring", "Polygon"), cex = 1)

geometries <- sf::st_sf(geometry = c(
  # POINT
  create_points(2, 2),
  # LINESTRING
  create_linestring(5, 1, 7, 3),
  # POLYGON
  create_polygon(9, 1, 9, 3, 11, 3, 11, 1),
  # MULTIPOINT
  sf::st_union(create_points(1, 7, 2, 6, 3, 5)),
  # MULTILINESTRING
  sf::st_union(
    create_linestring(5, 6, 6, 7),
    create_linestring(6, 5, 7, 6)
  ),
  # MULTIPOLYGON
  sf::st_union(
    create_polygon(9, 7, 10, 7, 10, 6, 9, 6),
    create_polygon(10, 5, 11, 6, 11, 5)
  )
))
plot(geometries, pch = 16, lwd = 2, add = TRUE)

# Get points from geometries
plot(get_points(geometries), pch = 16)

# Get linestrings from geometries
plot(get_linestrings(geometries), lwd = 2)

# Get polygons from geometries
plot(get_polygons(geometries), lwd = 2)

Filter points within a tolerance distance

Description

This function filters points that are within a specified tolerance distance from a reference linestring.

Usage

filter_points_within_tolerance(points, linestring, tolerance = 0.01)
filter_points_within_tolerance(points, linestring, tolerance = 0.01)

Arguments

`points`	A `sfc` object containing points to filter.
`linestring`	A linestring object.
`tolerance`	A numeric value representing the maximum allowable distance between points and the linestring. Points within this distance from the linestring will be included in the filtered set.

Value

A sfc object containing the filtered points.

Examples

# Create a points
points <- create_points(
  0.000, 1.000, 0.500, 0.600, 1.000, 0.010, 1.500, 0.501, 2.000, 0.990
)

# Create a linestring
linestring <- create_linestring(0, 1, 1, 0, 2, 1)

# Plot the points
plot(linestring, col = "gray")
plot(points, add = TRUE)

# Filter points within a tolerance distance (default: 0.01)
filtered_points <- filter_points_within_tolerance(points, linestring)

# Plot the filtered points
plot(linestring, col = "gray")
plot(filtered_points, add = TRUE)
# Create a points
points <- create_points(
  0.000, 1.000, 0.500, 0.600, 1.000, 0.010, 1.500, 0.501, 2.000, 0.990
)

# Create a linestring
linestring <- create_linestring(0, 1, 1, 0, 2, 1)

# Plot the points
plot(linestring, col = "gray")
plot(points, add = TRUE)

# Filter points within a tolerance distance (default: 0.01)
filtered_points <- filter_points_within_tolerance(points, linestring)

# Plot the filtered points
plot(linestring, col = "gray")
plot(filtered_points, add = TRUE)

Find the index of the duration that contains the event time

Description

This function find the index of the duration that contains the event time.

Usage

find_duration(events, durations, ...)
find_duration(events, durations, ...)

Arguments

`events`	A spatiotemporal event object.
`durations`	A duration object.
`...`	Additional arguments passed to or from other methods.

Value

A vector of indices corresponding to the durations that contain the event times.

Examples

# Create a spatiotemporal event object
accidents <- create_spatiotemporal_events(sample_accidents)

# Create a duration object
durations <- create_durations("1 hour")

# Find the duration that contains each accident
find_duration(accidents, durations)
# Create a spatiotemporal event object
accidents <- create_spatiotemporal_events(sample_accidents)

# Create a duration object
durations <- create_durations("1 hour")

# Find the duration that contains each accident
find_duration(accidents, durations)

Generate unique IDs based on parent IDs

Description

This function generates unique IDs based on parent IDs. It first extracts the first ID from each parent ID, then ranks these IDs and uses the ranks to format the IDs.

Usage

generate_ids(parent_list, id_format)
generate_ids(parent_list, id_format)

Arguments

`parent_list`	A list of parent IDs.
`id_format`	A format string for the IDs.

Value

A vector of unique IDs.

Examples

parent_list <- c("rd_0001", "rd_0002", "rd_0003")
id_format <- "jn_%06x"
generate_ids(parent_list, id_format)
parent_list <- c("rd_0001", "rd_0002", "rd_0003")
id_format <- "jn_%06x"
generate_ids(parent_list, id_format)

Get connected links from a specified node

Description

This function retrieves all links connected to a specified node in a road network.

Usage

get_connected_links(network, node_ids)
get_connected_links(network, node_ids)

Arguments

`network`	A `road_network` or `segmented_network` object.
`node_ids`	A vector of node IDs to find connected links for.

Value

A vector of link IDs connected to the specified node.

Examples

# Create a road network
road_network <- create_road_network(sample_roads)
target_node <- road_network$nodes[3,]$id
target_node

# Get connected links
connected_links <- get_connected_links(road_network, target_node)
connected_links

# Plot the target node and the connected links
is_connected <- road_network$links$id %in% connected_links
connected_links_geom <- road_network$links$geometry[is_connected]
plot(road_network, col = "gray")
plot(connected_links_geom, add = TRUE, col = "#E69F00", lwd = 2)
plot(road_network$nodes[3,]$geometry, add = TRUE, pch = 19)
# Create a road network
road_network <- create_road_network(sample_roads)
target_node <- road_network$nodes[3,]$id
target_node

# Get connected links
connected_links <- get_connected_links(road_network, target_node)
connected_links

# Plot the target node and the connected links
is_connected <- road_network$links$id %in% connected_links
connected_links_geom <- road_network$links$geometry[is_connected]
plot(road_network, col = "gray")
plot(connected_links_geom, add = TRUE, col = "#E69F00", lwd = 2)
plot(road_network$nodes[3,]$geometry, add = TRUE, pch = 19)

Japan Geodetic Datum 2011 (JDG2011) Reference Points

Description

A dataset representing reference points for Japan Geodetic Datum 2011 (JDG2011). This dataset contains system numbers, longitude, latitude, and corresponding coordinate reference system (CRS) codes for various geodetic reference points in Japan.

Usage

jdg2011_datum
jdg2011_datum

Format

A data.frame with 19 rows and 4 columns:

system_no: System number (Roman numeral I-XIX) representing geodetic reference zones
lon: Longitude in decimal degrees
lat: Latitude in decimal degrees
crs: Coordinate reference system (CRS) code for reference point

Examples

# Show the dataset
jdg2011_datum

# Show the dataset
jdg2011_datum

Values for the 'highway' tag in OpenStreetMap data

Description

osm_highway_values contains a character vector of values for the 'highway' tag in OpenStreetMap data.

Usage

osm_highway_values
osm_highway_values

Format

A character vector of length 12.

Examples

osm_highway_values
osm_highway_values

Plot a road network

Description

This function plots a road network.

Usage

## S3 method for class 'road_network'
plot(x, y, mode = c("default", "event", "graph"), ...)
## S3 method for class 'road_network'
plot(x, y, mode = c("default", "event", "graph"), ...)

Arguments

`x`	A road network object.
`y`	This argument is not used.
`mode`	The plotting mode. "event" mode shows the location events assigned to the road network. "graph" mode shows the direction of links when the network is directed. This utilizes the `plot.igraph` function.
`...`	Additional arguments passed to or from other methods.

Examples

# Create the road network
road_network <- create_road_network(sample_roads, events = sample_accidents)

# Plot the road network
plot(road_network)

# Plot the road network with events
plot(road_network, mode = "event")

# Plot the road network as a graph
plot(road_network, mode = "graph")
# Create the road network
road_network <- create_road_network(sample_roads, events = sample_accidents)

# Plot the road network
plot(road_network)

# Plot the road network with events
plot(road_network, mode = "event")

# Plot the road network as a graph
plot(road_network, mode = "graph")

Remove points near endpoints of a linestring

Description

This function removes points from a set of points that are within a specified tolerance distance of the start or end point of a linestring.

Usage

remove_points_near_endpoints(points, linestring, tolerance = 0.01)
remove_points_near_endpoints(points, linestring, tolerance = 0.01)

Arguments

`points`	A `sfc` object containing points to filter.
`linestring`	A linestring object.
`tolerance`	A numeric value representing the maximum distance from the line's ends to consider points for filtering. Points within this distance will be excluded.

Value

A sfc object containing the filtered points.

Examples

# Create a points
points <- create_points(
  0.000, 1.000, 0.500, 0.600, 1.000, 0.010, 1.500, 0.501, 2.000, 0.990
)

# Create a linestring
linestring <- create_linestring(0, 1, 1, 0, 2, 1)

# Plot the points
plot(linestring, col = "gray")
plot(points, add = TRUE)

# Filter points within a tolerance distance (default: 0.01)
filtered_points <- remove_points_near_endpoints(points, linestring)

# Plot the filtered points
plot(linestring, col = "gray")
plot(filtered_points, add = TRUE)
# Create a points
points <- create_points(
  0.000, 1.000, 0.500, 0.600, 1.000, 0.010, 1.500, 0.501, 2.000, 0.990
)

# Create a linestring
linestring <- create_linestring(0, 1, 1, 0, 2, 1)

# Plot the points
plot(linestring, col = "gray")
plot(points, add = TRUE)

# Filter points within a tolerance distance (default: 0.01)
filtered_points <- remove_points_near_endpoints(points, linestring)

# Plot the filtered points
plot(linestring, col = "gray")
plot(filtered_points, add = TRUE)

Create a road network from roads

Description

This function constructs a road network from a set of roads. The road network is represented nodes and links between nodes. Nodes are defined as intersections between roads and endpoints of road segments.

Usage

create_road_network(roads, directed = FALSE, events = NULL, ...)
create_road_network(roads, directed = FALSE, events = NULL, ...)

Arguments

`roads`	A linestring object representing roads.
`directed`	Logical indicating whether the road network is directed.
`events`	A `sf` object representing events.
`...`	Additional arguments passed to or from other methods.

Value

A road network object.

Examples

# Create the road network
road_network <- create_road_network(sample_roads)

# Print the road network summary
road_network

# Plot the road network
plot(road_network)
# Create the road network
road_network <- create_road_network(sample_roads)

# Print the road network summary
road_network

# Plot the road network
plot(road_network)

Sample accidents data

Description

A sample dataset containing information about 10 accidents. The dataset is for demonstration and testing and does not represent real-world events.

Usage

sample_accidents
sample_accidents

Format

A sf object with 10 rows and 4 columns:

id: Accident ID
time: Time of the accident (in hours)
weather: Weather condition at the time of the accident
severity: Severity of the accident
geometry: Point geometry of the accident location

Examples

# Show information about the accidents
sample_accidents

# Plot the locations of the accidents
plot(sample_roads$geometry)
plot(sample_accidents$geometry, pch = 4, col = "red", add = TRUE)
# Show information about the accidents
sample_accidents

# Plot the locations of the accidents
plot(sample_roads$geometry)
plot(sample_accidents$geometry, pch = 4, col = "red", add = TRUE)

Sample points along a linestring

Description

This function samples points at regular intervals along a linestring object.

Usage

sample_points_along_linestring(linestrings, segment_length)
sample_points_along_linestring(linestrings, segment_length)

Arguments

`linestrings`	A `sfc` object containing linestrings.
`segment_length`	The desired length of each segment between sampled points.

Value

A sfc object containing the sampled points.

Examples

library(sf)

# Create a linestrings
linestrings <- c(
  create_linestring(0, 1, 2, 1),
  create_linestring(1, 1.3, 1, 0, 2, 0.5)
)

# Sample points along the linestrings
sampled_points <- sample_points_along_linestring(linestrings, 0.5)

# Plot the sampled points
plot(linestrings)
plot(sampled_points, add = TRUE, pch = 16, col = c("#E69F00", "#56B4E9"))
library(sf)

# Create a linestrings
linestrings <- c(
  create_linestring(0, 1, 2, 1),
  create_linestring(1, 1.3, 1, 0, 2, 0.5)
)

# Sample points along the linestrings
sampled_points <- sample_points_along_linestring(linestrings, 0.5)

# Plot the sampled points
plot(linestrings)
plot(sampled_points, add = TRUE, pch = 16, col = c("#E69F00", "#56B4E9"))

Sample roads data

Description

A sample dataset representing simple roads. It intended for demonstration and testing and does not represent real-world roads.

Usage

sample_roads
sample_roads

Format

A sf linestring object with 6 rows and 2 columns:

id: Road ID
layer: Layer of the road (indicates a road on an elevated structure such as a bridge, tunnel, or highway)
geometry: Linestring geometry of the road

Examples

# Show information about the roads
sample_roads

# Shape of the roads
plot(sample_roads$geometry)
# Show information about the roads
sample_roads

# Shape of the roads
plot(sample_roads$geometry)

Create a segmented road network

Description

This function creates a segmented road network by dividing each link of the input road network into segments of a specified length.

Usage

create_segmented_network(road_network, segment_length = 1, events = NULL, ...)

## S3 method for class 'road_network'
create_segmented_network(road_network, segment_length = 1, events = NULL, ...)
create_segmented_network(road_network, segment_length = 1, events = NULL, ...)

## S3 method for class 'road_network'
create_segmented_network(road_network, segment_length = 1, events = NULL, ...)

Arguments

`road_network`	A `road_network` object representing the input road network.
`segment_length`	A numeric value specifying the length of each segment.
`events`	A `sf` object representing events.
`...`	Additional arguments passed to or from other methods.

Value

A segmented_network object.

Examples

# Create a road network
road_network <- create_road_network(sample_roads)

# Create a segmented road network
segmented_network <- create_segmented_network(
  road_network,
  segment_length = 0.5
)
segmented_network

# Plot the segmented road network
plot(segmented_network)
# Create a road network
road_network <- create_road_network(sample_roads)

# Create a segmented road network
segmented_network <- create_segmented_network(
  road_network,
  segment_length = 0.5
)
segmented_network

# Plot the segmented road network
plot(segmented_network)

Set events on a space.

Description

This function sets events on a space.

Usage

set_events(x, events, ...)
set_events(x, events, ...)

Arguments

`x`	A space object.
`events`	A sf or spatiotemporal events object.
`...`	Additional arguments passed to or from other methods.

Value

The input object with the events added.

Examples

# Create the road network
road_network <- create_road_network(sample_roads)

# Set accidents on the road network
road_network <- set_events(road_network, sample_accidents)
# Create the road network
road_network <- create_road_network(sample_roads)

# Set accidents on the road network
road_network <- set_events(road_network, sample_accidents)

Create a spatiotemporal event collection

Description

This function creates a spatiotemporal event collection object from a given sf object, allowing spatial and temporal data to be handled together.

Usage

create_spatiotemporal_events(x, ...)

## S3 method for class 'sf'
create_spatiotemporal_events(
  x,
  time_column_name = "time",
  time_format = "%H",
  ...
)
create_spatiotemporal_events(x, ...)

## S3 method for class 'sf'
create_spatiotemporal_events(
  x,
  time_column_name = "time",
  time_format = "%H",
  ...
)

Arguments

`x`	A `sf` object representing the spatial data.
`...`	Additional arguments passed to or from other methods.
`time_column_name`	A character string specifying the column name in `x` that contains time-related data. Defaults to `"time"`
`time_format`	A character string specifying the format of the time data in the `time_column_name`. For example, you can use formats like `"%Y-%m-%d"` for dates or `"%H:%M:%S"` for time. Defaults to `"%H"`.

Value

An sf object with class spatiotemporal_events added, representing a spatiotemporal event collection.

Examples

# Simple feature collection object representing accidents
sample_accidents

# Create a spatiotemporal event collection
create_spatiotemporal_events(sample_accidents)
# Simple feature collection object representing accidents
sample_accidents

# Create a spatiotemporal event collection
create_spatiotemporal_events(sample_accidents)

Create spatiotemporal network

Description

This function creates a spatiotemporal network from a road network.

Usage

create_spatiotemporal_network(
  road_network,
  spatial_length = 1,
  temporal_length = "1 hour",
  events = NULL,
  ...
)
create_spatiotemporal_network(
  road_network,
  spatial_length = 1,
  temporal_length = "1 hour",
  events = NULL,
  ...
)

Arguments

`road_network`	A `road_network` object.
`spatial_length`	The spatial length of segment.
`temporal_length`	The temporal length of segment.
`events`	A event collection object.
`...`	Additional arguments passed to or from other methods.

Value

A spatiotemporal_network object.

Examples

# Create a road network
road_network <- create_road_network(sample_roads)

# Create a spatiotemporal road network
spatiotemporal_network <- create_spatiotemporal_network(
  road_network,
  spatial_length = 0.5,
  temporal_length = "4 hour"
)
spatiotemporal_network

# Plot the spatiotemporal road network
plot(spatiotemporal_network)
# Create a road network
road_network <- create_road_network(sample_roads)

# Create a spatiotemporal road network
spatiotemporal_network <- create_spatiotemporal_network(
  road_network,
  spatial_length = 0.5,
  temporal_length = "4 hour"
)
spatiotemporal_network

# Plot the spatiotemporal road network
plot(spatiotemporal_network)

Split a linestring into multiple segments

Description

Split a linestring into multiple segments

Usage

split_linestring(linestring, split_points, tolerance = 0.01)
split_linestring(linestring, split_points, tolerance = 0.01)

Arguments

`linestring`	A linestring object.
`split_points`	A `sfc` object containing points to split the linestring.
`tolerance`	A numeric value representing the maximum distance allowed between the linestring and the split points. If the distance between a split point and the linestring exceeds this value, the point will not be used to split the linestring.

Value

A sfc object containing the split linestrings.

Examples

# Create a linestring
linestring <- create_linestring(0, -1, 0, 1, 2, 1, 2, 0, 0, 0)

# Create a set of split points
split_points <- create_points(0, 0, 1, 1, 2, 0)

# Plot the linestring and split points
plot(linestring)
plot(split_points, add = TRUE)

# Split the linestring
segments <- split_linestring(linestring, split_points)

# Plot the split linestrings
plot(segments, col = c("#E69F00", "#56B4E9", "#009E73", "#F0E442"), lwd = 2)
# Create a linestring
linestring <- create_linestring(0, -1, 0, 1, 2, 1, 2, 0, 0, 0)

# Create a set of split points
split_points <- create_points(0, 0, 1, 1, 2, 0)

# Plot the linestring and split points
plot(linestring)
plot(split_points, add = TRUE)

# Split the linestring
segments <- split_linestring(linestring, split_points)

# Plot the split linestrings
plot(segments, col = c("#E69F00", "#56B4E9", "#009E73", "#F0E442"), lwd = 2)

Transform to Cartesian or geographic coordinates

Description

This function transforms a spatial object to Cartesian coordinates (plane rectangular coordinate system) or geographic coordinates (WGS84; EPSG:4326). The Cartesian system currently supports only Aichi Prefecture's JDG2011 system (EPSG:6675).

Usage

transform_coordinates(
  spatial_object,
  target = c("cartesian", "geographic"),
  quiet = FALSE
)

transform_to_cartesian(spatial_object, quiet = FALSE)

transform_to_geographic(spatial_object, quiet = FALSE)
transform_coordinates(
  spatial_object,
  target = c("cartesian", "geographic"),
  quiet = FALSE
)

transform_to_cartesian(spatial_object, quiet = FALSE)

transform_to_geographic(spatial_object, quiet = FALSE)

Arguments

`spatial_object`	A spatial object.
`target`	A character string specifying the target coordinate system: `"cartesian"` (EPSG:6675) or `"geographic"` (EPSG:4326).
`quiet`	Logical. If `TRUE`, suppresses the warning when CRS is missing.

Details

If the CRS is missing (NA), a warning is issued, and the original object is returned. The warning can be suppressed with the quiet argument.

Value

A spatial object transformed to the specified coordinate system.

Examples

# Create points
points <- create_points(136.9024, 35.1649, crs = 4326)
points

# Transform to Cartesian coordinates
transformed <- transform_to_cartesian(points)
transformed

# Transform to geographic coordinates
transformed <- transform_to_geographic(points)
transformed
# Create points
points <- create_points(136.9024, 35.1649, crs = 4326)
points

# Transform to Cartesian coordinates
transformed <- transform_to_cartesian(points)
transformed

# Transform to geographic coordinates
transformed <- transform_to_geographic(points)
transformed

Package 'pavement'

Help Index

Compute the Epanechnikov function

Description

Usage

Arguments

Value

Examples

Compute the Gaussian function

Description

Usage

Arguments

Value

Examples

Convert a bounding box to coordinates or a polygon

Description

Usage

Arguments

Value

Examples

Convolute segmented road network

Description

Usage

Arguments

Value

References

Examples

Create a bounding box

Description

Usage

Arguments

Value

Examples

Create a collection of coordinates.

Description

Usage

Arguments

Value

Examples

Create a graph from nodes and links

Description

Usage

Arguments

Value

Examples

Create a line graph from a network

Description

Usage

Arguments

Value

Examples

Create a linestring geometry

Description

Usage

Arguments

Value

Examples

Create points geometry

Description

Usage

Arguments

Value

Examples

Create a polygon geometry

Description

Usage

Arguments

Value

Examples

Decompose a linestring into a list of line segments

Description

Usage

Arguments

Value

Examples

Create durations

Description

Usage

Arguments

Value