R: Identify regions on a map

identify.map {maps} | R Documentation

## Identify regions on a map

### Description

Identifies the map regions clicked by the user.

### Usage

    ## S3 method for class 'map'
    identify(x, n = 1, index = FALSE, ...)

### Arguments

`x` | a map object containing named polygons.
`n` | the number of clicks to wait for.
`index` | If TRUE, returns the index of the polygon, rather than its name.
`...` | additional arguments passed to `identify.default`.

### Details

The current algorithm is somewhat crude — selects the region whose centroid is closest to the click. A more sophisticated approach would use `map.where`.

### Value

a character vector of length `n`, naming the selected regions.

### Author(s)

Tom Minka

### See Also

`identify`, `map.where`

### Examples

    identify(map("state", fill = TRUE, col = 0))
    if(require(mapproj))
      identify(map("world", proj = "lagrange", fill = TRUE, col = 0, wrap=c(-180,180,-90)))

[Package maps version 3.3.0 Index]