R: Graphical Input

locator {base} | R Documentation

## Graphical Input

### Description

Reads the position of the graphics cursor when the (first) mouse button is pressed.

### Usage

    locator(n = 512, type = "n", ...)

### Arguments

`n` | the maximum number of points to locate.
`type` | One of `"n"`, `"p"`, `"l"` or `"o"`. If `"p"` or `"o"` the points are plotted; if `"l"` or `"o"` they are joined by lines.
`...` | additional graphics parameters used if `type != "n"` for plotting the locations.

### Details

Unless the process is terminated prematurely by the user (see below) at most `n` positions are determined.

The identification process can be terminated by pressing any mouse button other than the first.

The current graphics parameters apply just as if `plot.default` has been called with the same value of `type`. The plotting of the points and lines is subject to clipping, but locations outside the current clipping rectangle will be returned.

If the window is resized or hidden and then exposed before the input process has terminated, any lines or points drawn by `locator` will disappear. These will reappear once the input process has terminated and the window is resized or hidden and exposed again. This is because the points and lines drawn by `locator` are not recorded in the device's display list until the input process has terminated.

### Value

A list containing `x` and `y` components which are the coordinates of the identified points.

### See Also

`identify`

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