#NEWLINE# def plot_interval( self , parameter = 't' ) : #NEWLINE# #INDENT# "The plot interval for the default geometric plot of line. Gives\n        values that will produce a line that is +/- 5 units long (where a\n        unit is the distance between the two points that define the line).\n\n        Parameters\n        ==========\n\n        parameter : str, optional\n            Default value is 't'.\n\n        Returns\n        =======\n\n        plot_interval : list (plot interval)\n            [parameter, lower_bound, upper_bound]\n\n        Examples\n        ========\n\n        >>> from sympy import Point3D, Line3D\n        >>> p1, p2 = Point3D(0, 0, 0), Point3D(5, 3, 1)\n        >>> l1 = Line3D(p1, p2)\n        >>> l1.plot_interval()\n        [t, -5, 5]\n\n        " #NEWLINE# t = _symbol ( parameter ) #NEWLINE# return [ self , ( - 5 ) , 5 ]