R: Measure distance from plot

airdist {spdep} | R Documentation

## Measure distance from plot

### Description

Measure a distance between two points on a plot using `locator`; the function checks `par("plt")` and `par("usr")` to try to ensure that the aspect ratio y/x is 1, that is that the units of measurement in both x and y are equivalent.

### Usage

    airdist(ann=FALSE)

### Arguments

`ann` | annotate the plot with line measured and distance

### Value

a list with members:

`dist` | distance measured
`coords` | coordinates between which distance is measured

### Author(s)

Roger Bivand Roger.Bivand@nhh.no

### See Also

`locator`

[Package spdep version 0.6-13 Index]