Opens a new device.
devNew(type=getOption("device"), ..., scale=1, aspectRatio=1, par=NULL, label=NULL)Returns the device index of the opened device.
A character string specifying the type of device to be
    opened. This string should match the name of an existing device
    function.
Additional arguments passed to the device function, e.g.
    width and height.  If not given, the are inferred
    from devOptions().
A numeric scalar factor specifying how much the
    width and the height should be rescaled.
A numeric ratio specifying the aspect ratio
    of the image.  See below.
An optional named list of graphical settings applied,
    that is, passed to par, immediately after
    opening the device.
An optional character string specifying the label of the
    opened device.
The default width and height of the generated image is specific to
  the type of device used.  There is not straightforward programmatic
  way to infer these defaults; here we use devOptions(), which
  in most cases returns the correct defaults.
The aspect ratio of an image is the height relative to the width.
  If argument height is not given (or NULL), it is
  calculated as aspectRatio*width as long as they are given.
  Likewise, if argument width is not given (or NULL), it is
  calculated as width/aspectRatio as long as they are given.
  If neither width nor height is given, then width
  defaults to devOptions(type)$width.
  If both width and height are given, then
  aspectRatio is ignored.
Henrik Bengtsson
devDone() and devOff().
  For simplified generation of image files, see devEval().