  plpoin(n, x, y, code)
  *********************

  plpoin

  Marks out a set of n points at positions (x(i), y(i)), using the symbol
  defined by code. If code is between 32 and 127, the symbol is simply the
  printable ASCII character in the default font.

  n (PLINT, input): Number of points to be marked.

  x (PLFLT *, input): Pointer to array with set of x coordinate values for
  the points.

  y (PLFLT *, input): Pointer to array with set of y coordinate values for
  the points.

  code (PLINT, input): Code number for the symbol to be plotted.

