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Find which nodes fall in a given area

Source: R/isInArea.R
isInArea.Rd

The generic function isInArea finds which nodes fall in a given area. Nodes can be specified in different ways, including by providing a gGraph or a gData object. Different formats for the output are also available. The area can be defined interactively (current plot window), from the zoom log, or explicitly by providing a bounding box.

Usage

isInArea(x, ...)

# S4 method for class 'matrix'
isInArea(
  x,
  reg = "current",
  res.type = c("logical", "integer", "character"),
  buffer = 0,
  quiet = FALSE
)

# S4 method for class 'data.frame'
isInArea(
  x,
  reg = "current",
  res.type = c("logical", "integer", "character"),
  buffer = 0,
  quiet = FALSE
)

# S4 method for class 'gGraph'
isInArea(
  x,
  reg = "current",
  res.type = c("logical", "integer", "character"),
  buffer = 0,
  quiet = FALSE
)

# S4 method for class 'gData'
isInArea(
  x,
  reg = "current",
  res.type = c("logical", "integer", "character"),
  buffer = 0,
  quiet = FALSE
)

Arguments

x

a matrix, data.frame, valid gGraph, or valid gData object. For matrix and data.frame, input must have two columns giving longitudes and latitudes of locations being considered.

...

further arguments passed to specific methods.

reg

a character string or a list indicating the area. Character strings can be "current" (current user window, default) or "zoom" (current zoom). If a list, it must have two components, both being numeric vectors of length two, giving x and y limits of the area, e.g. list(x = c(-10, 30), y = c(35, 70)). A list produced by locator() is also a valid value.

res.type

a character string indicating what kind of output should be produced. See value.

buffer

a numeric value giving a buffer adding extra space around the area, as a proportion of current area's dimensions.

quiet

logical. If TRUE, suppresses printing of bounding box coordinates and a reproducible reg argument that can be copy-pasted into scripts for exact reproducibility. Defaults to FALSE.

Value

The output depends on the value of the argument res.type:

  • "logical": a vector of logicals having one value for each node.

  • "integer": a vector of integers corresponding to the indices of nodes falling within the area.

  • "character": a vector of characters corresponding to the names of the nodes falling within the area.

Functions

  • isInArea(matrix): Method for matrix

  • isInArea(data.frame): Method for data.frame

  • isInArea(gGraph): Method for gGraph object

  • isInArea(gData): Method for gData object

See also

geo.zoomin to zoom into an area. gGraph and gData for the input object classes.

Examples


## Zoom into Europe and get the nodes in the current plot
plot(worldgraph.10k, reset = TRUE)
#> Spherical geometry (s2) switched off

#> Spherical geometry (s2) switched on
geo.zoomin(list(x = c(-6, 38), y = c(35, 73)))
#> Spherical geometry (s2) switched off

#> Spherical geometry (s2) switched on

## Different output formats of the current nodes
head(isInArea(worldgraph.10k, quiet = TRUE))
#>     1     2     3     4     5     6 
#> FALSE FALSE FALSE FALSE FALSE FALSE 
head(isInArea(worldgraph.10k, res.type = "integer", quiet = TRUE))
#>  707  965 1027 1028 1029 1285 
#>  707  965 1027 1028 1029 1285 
head(isInArea(worldgraph.10k, res.type = "character", quiet = TRUE))
#> [1] "707"  "965"  "1027" "1028" "1029" "1285"

## subset the gGraph just to visible nodes
x <- worldgraph.10k[isInArea(worldgraph.10k)]
#> Area: lon = [-29.4479, 61.4479], lat = [30.2400, 77.7600]
#> 
#>       Reproducible call: reg = list(x = c(-29.4479, 61.4479), y = c(30.2400, 77.7600))
plot(x, reset = TRUE)
#> Spherical geometry (s2) switched off

#> Spherical geometry (s2) switched on

## Instead of the current plotted area we can use an explicit bounding box
y <- worldgraph.10k[(isInArea(worldgraph.10k,
  reg = list(x = c(113, 154), y = c(-44, -10)),
  quiet = TRUE
))]
plot(y, reset = TRUE)
#> Spherical geometry (s2) switched off

#> Spherical geometry (s2) switched on