  plstart(device, nx, ny)
  ***********************

  plstart

  Alternative to plstar for initializing the plotting package. The device
  name keyword for the desired output device must be supplied as an argument.
  The device keywords are the same as those printed out by plstar. If the
  requested device is not available, or if the input string is empty or
  begins with ``?'', the prompted startup of plstar is used. This routine
  also divides the output device into nx by ny sub-pages, each of which may
  be used independently. The subroutine pladv is used to advance from one
  subpage to the next.

  device (char *, input): Device name (keyword) of the required output
  device. If NULL or if the first character is a ``?'', the normal (prompted)
  startup is used.

  nx (PLINT, input): Number of subpages to divide output page in the
  horizontal direction.

  ny (PLINT, input): Number of subpages to divide output page in the
  vertical direction.

