Package 'zonebuilder'

Region representing London in projected coordinate system

Description

'london_a()' and 'london_c()' return the city boundaries and centre point of London, respectively.

Usage

london_a()

london_c()

Note

'london_a()' returns a projected version of 'lnd' in 'spDataLarge'. See the ‘data-raw' folder in the package’s repo to reproduce these datasets The 'lonlat' versions of the data have coordinates in units of degrees.

Examples

plot(london_a(), reset = FALSE)
plot(london_c(), add = TRUE)

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The first 100 triangular numbers

Description

The first 100 in the sequence of [triangular numbers](https://en.wikipedia.org/wiki/Triangular_number)

Note

See the ‘data-raw' folder in the package’s repo to reproduce these datasets

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Generate colors for zones

Description

This function generates colors for zones.

Usage

zb_color(z, palette = c("rings", "hcl", "dartboard"))

Arguments

z	An 'sf' object containing zones covering the region
palette	Palette type, one of "hcl" (a palette based on the HCL color space), "rings" (a palette which colors the rings using the YlOrBr color brewer palette), "dartboard" (a palette which resembles a dartboard)

Value

A vector of colors

Examples

z = zb_zone(london_c(), london_a())
zb_color(z)
plot(z[, "circle_id"], col = zb_color(z))

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Make doughnuts

Description

Make doughnuts

Usage

zb_doughnut(
  x = NULL,
  area = NULL,
  n_circles = NA,
  distance = 1,
  distance_growth = 1
)

Arguments

x	Centre point. Should be an sf or sfc object containing one point, or a name of a city (which is looked up with OSM geocoding).
area	(optional) Area. Should be an sf or sfc object containing one (multi) polygon
n_circles	Number of rings including the central circle. By default 5, unless area is specified (then it is set automatically to fill the area).
distance	Distance The distances between the circles. For the center circle, it is the distance between the center and the circle. If only one number is specified, distance_growth determines the increment at which the distances grow for the outer circles.
distance_growth	The rate at which the distances between the circles grow. Only applicable when distance is one number and n_circles > 1. See also distance.

Value

An 'sf' data frame

Examples

zb_plot(zb_doughnut(london_c(), london_a()))

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Create lines radiating at equal angles from a point

Description

Create lines radiating at equal angles from a point

Usage

zb_lines(point, n, starting_angle = 45, distance = 1e+05)

Arguments

point	Center point
n	Number of lines
starting_angle	Starting angle
distance	Distance

Value

Objects of class 'sfc' containing linestring geometries

Examples

point = sf::st_centroid(london_a())
n = 4
l = zb_lines(point, n)
plot(l)

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Plot zones

Description

This function opens a static map of the zones

Usage

zb_plot(
  z,
  palette = c("rings", "hcl", "dartboard"),
  title = NULL,
  text_size = c(0.3, 1),
  zone_label_thres = 0.002
)

Arguments

z	An 'sf' object containing zones covering the region
palette	Palette type, one of "hcl" (a palette based on the HCL color space), "rings" (a palette which colors the rings using the YlOrBr color brewer palette), "dartboard" (a palette which resembles a dartboard)
title	Plot title
text_size	Vector of two numeric values that determine the relative text sizes. The first determines the smallest text size and the second one the largest text size. The largest text size is used for the outermost circle, and the smallest for the central circle in case there are 9 or more circles. If there are less circles, the relative text size is larger (see source code for exact method)
zone_label_thres	This number determines in which zones labels are printed, namely each zone for which the relative area size is larger than 'zone_label_thres'.

Value

A static plot created using R's base 'graphics' package

Examples

zb_plot(zb_zone(london_c()))

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Divide a region into quadrats

Description

Divide a region into quadrats

Usage

zb_quadrat(x, ncol, nrow = NULL, intersection = TRUE)

Arguments

x	x
ncol	ncol
nrow	nrow
intersection	intersection

Value

An sf object

Examples

x = london_a()
c = sf::st_centroid(london_a())
plot(zb_quadrat(x, ncol = 2), col = 2:5)
plot(c, add = TRUE, col = "white")
plot(zb_quadrat(x, ncol = 3))
plot(zb_quadrat(x, ncol = 4))
plot(zb_quadrat(x, ncol = 4, intersection = FALSE))

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Make segments

Description

Make segments

Usage

zb_segment(x = NULL, area = NULL, n_segments = 12, distance = NA)

Arguments

x	Centre point. Should be an sf or sfc object containing one point, or a name of a city (which is looked up with OSM geocoding).
area	(optional) Area. Should be an sf or sfc object containing one (multi) polygon
n_segments	(optional) Number of segments. The number of segments. Either one number which determines the number of segments applied to all circles, or a vector with a number for each circle (which should be a multiple of 4, see also the argument labeling). By default, the central circle is not segmented (see the argument segment_center).
distance	Distance The distances between the circles. For the center circle, it is the distance between the center and the circle. If only one number is specified, distance_growth determines the increment at which the distances grow for the outer circles.

Value

An 'sf' data frame

Examples

zb_plot(zb_segment(london_c(), london_a()))

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View zones

Description

This function opens an interactive map of the zones

Usage

zb_view(z, alpha = 0.4, palette = c("rings", "hcl", "dartboard"), title = NULL)

Arguments

z	An 'sf' object containing zones covering the region
alpha	Alpha transparency, number between 0 (fully transparent) and 1 (not transparent)
palette	Palette type, one of "hcl" (a palette based on the HCL color space), "rings" (a palette which colors the rings using the YlOrBr color brewer palette), "dartboard" (a palette which resembles a dartboard)
title	The title of the plot

Value

An interactive map created with 'tmap'

Examples

z = zb_zone(london_c(), london_a())
zb_view(z, palette = "rings")

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Generate zones covering a region of interest

Description

This function first divides geographic space into [annuli](https://en.wikipedia.org/wiki/Annulus_(mathematics)) (concentric 2d rings or 'doughnuts') and then subdivides each annulus into a number of segments.

Usage

zb_zone(
  x = NULL,
  area = NULL,
  n_circles = NA,
  n_segments = 12,
  distance = 1,
  distance_growth = 1,
  labeling = NA,
  starting_angle = NA,
  segment_center = FALSE,
  intersection = TRUE,
  city = NULL
)

Arguments

x	Centre point. Should be an sf or sfc object containing one point, or a name of a city (which is looked up with OSM geocoding).
area	(optional) Area. Should be an sf or sfc object containing one (multi) polygon
n_circles	Number of rings including the central circle. By default 5, unless area is specified (then it is set automatically to fill the area).
n_segments	(optional) Number of segments. The number of segments. Either one number which determines the number of segments applied to all circles, or a vector with a number for each circle (which should be a multiple of 4, see also the argument labeling). By default, the central circle is not segmented (see the argument segment_center).
distance	Distance The distances between the circles. For the center circle, it is the distance between the center and the circle. If only one number is specified, distance_growth determines the increment at which the distances grow for the outer circles.
distance_growth	The rate at which the distances between the circles grow. Only applicable when distance is one number and n_circles > 1. See also distance.
labeling	The labeling of the zones. Either "clock" which uses the clock ananolgy (i.e. hours 1 to 12) or "NESW" which uses the cardinal directions N, E, S, W. If the number of segments is 12, the clock labeling is used, and otherwise NESW. Note that the number of segments should be a multiple of four. If, for instance the number of segments is 8, than the segments are labeled N1, N2, E1, E2, S1, S2, W1, and W2.
starting_angle	The angle of the first of the radii that create the segments (degrees). By default, it is either 15 when n_segments is 12 (i.e. the ClockBoard setting) and -45 otherwise.
segment_center	Should the central circle be divided into segments? 'FALSE' by default.
intersection	Should the zones be intersected with the area? TRUE by default.
city	(optional) Name of the city. If specified, it adds a column 'city' to the returned 'sf' object.

Details

By default 12 segments are used for each annuli, resulting in a zoning system that can be used to refer to segments in [clock position](https://en.wikipedia.org/wiki/Clock_position), with 12 representing North, 3 representing East, 6 Sounth and 9 Western segments.

Value

An 'sf' object containing zones covering the region

Examples

# default settings
z = zb_zone(london_c(), london_a())

zb_plot(z)
if (require(tmap)) {
  zb_view(z)
  
  z = zb_zone("Berlin")
  zb_view(z)
}

# variations
zb_plot(zb_zone(london_c(), london_a(), n_circles = 2))
zb_plot(zb_zone(london_c(), london_a(), n_circles = 4, distance = 2, distance_growth = 0))
zb_plot(zb_zone(london_c(), london_a(), n_circles = 3, n_segments = c(1,4,8)))

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