dev {grDevices} | R Documentation

## Control Multiple Devices

### Description

These functions provide control over multiple graphics devices.

### Usage

    dev.cur()
    dev.list()
    dev.next(which = dev.cur())
    dev.prev(which = dev.cur())
    dev.off(which = dev.cur())
    dev.set(which = dev.next())
    dev.new(...)
    graphics.off()

### Arguments

`which` | An integer specifying a device number.
`...` | arguments to be passed to the device selected.

### Details

Only one device is the ‘active’ device: this is the device in which all graphics operations occur. There is a `"null device"` which is always open but is really a placeholder: any attempt to use it will open a new device specified by `getOption("device")`).

Devices are associated with a name (e.g., `"X11"` or `"postscript"`) and a number in the range 1 to 63; the `"null device"` is always device 1. Once a device has been opened the null device is not considered as a possible active device. There is a list of open devices, and this is considered as a circular list not including the null device. `dev.next` and `dev.prev` select the next open device in the appropriate direction, unless no device is open.

`dev.off` shuts down the specified (by default the current) device. If the current device is shut down and any other devices are open, the next open device is made current. It is an error to attempt to shut down device 1. `graphics.off()` shuts down all open graphics devices. Normal termination of a session runs the internal equivalent of `graphics.off()`.

`dev.set` makes the specified device the active device. If there is no device with that number, it is equivalent to `dev.next`. If `which = 1` it opens a new device and selects that.

`dev.new` opens a new device. Normally R will open a new device automatically when needed, but this enables you to open further devices in a platform-independent way. (For which device is used see `getOption("device")`.) Note that care is needed with file-based devices such as `pdf` and `postscript` and in that case file names such as ‘Rplots.pdf’, ‘Rplots1.pdf’, ..., ‘Rplots999.pdf’ are tried in turn. Only named arguments are passed to the device, and then only if they match the argument list of the device. Even so, care is needed with the interpretation of e.g. `width`, and for the standard bitmap devices `units="in", res=72` is forced if neither is supplied but both `width` and `height` are.

### Value

`dev.cur` returns a length-one named integer vector giving the number and name of the active device, or 1, the null device, if none is active.

`dev.list` returns the numbers of all open devices, except device 1, the null device. This is a numeric vector with a `names` attribute giving the device names, or `NULL` is there is no open device.

`dev.next` and `dev.prev` return the number and name of the next / previous device in the list of devices. This will be the null device if and only if there are no open devices.

`dev.off` returns the number and name of the new active device (after the specified device has been shut down).

`dev.set` returns the number and name of the new active device.

`dev.new` returns the return value of the device opened, usually invisible `NULL`.

### See Also

`Devices`, such as `postscript`, etc.

`layout` and its links for setting up plotting regions on the current device.

### Examples

    ## Not run: ## Unix-specific example
    x11()
    plot(1:10)
    x11()
    plot(rnorm(10))
    dev.set(dev.prev())
    abline(0,1)# through the 1:10 points
    dev.set(dev.next())
    abline(h=0, col="gray")# for the residual plot
    dev.set(dev.prev())
    dev.off(); dev.off()#- close the two X devices

    ## End(Not run)

[Package grDevices version 2.15.2 Index]