grid.segments              package:grid              R Documentation

_D_r_a_w _L_i_n_e _S_e_g_m_e_n_t_s

_D_e_s_c_r_i_p_t_i_o_n:

     These functions create and draw line segments.

_U_s_a_g_e:

     grid.segments(x0 = unit(0, "npc"), y0 = unit(0, "npc"),
                   x1 = unit(1, "npc"), y1 = unit(1, "npc"),
                   default.units = "npc", units.per.obs = FALSE,
                   arrow = NULL,
                   name = NULL, gp = gpar(), draw = TRUE, vp = NULL)
     segmentsGrob(x0 = unit(0, "npc"), y0 = unit(0, "npc"),
                   x1 = unit(1, "npc"), y1 = unit(1, "npc"),
                   default.units = "npc", units.per.obs = FALSE,
                   arrow = NULL, name = NULL, gp = gpar(), vp = NULL)

_A_r_g_u_m_e_n_t_s:

      x0: Numeric indicating the starting x-values of the line
          segments. 

      y0: Numeric indicating the starting y-values of the line
          segments. 

      x1: Numeric indicating the stopping x-values of the line
          segments. 

      y1: Numeric indicating the stopping y-values of the line
          segments.

default.units: A string. 

units.per.obs: A boolean indicating whether distinct units are given
          for each x/y-value. 

   arrow: A list describing arrow heads to place at either end of the
          line segments, as produced by the 'arrow' function.

    name: A character identifier. 

      gp: An object of class 'gpar'. 

    draw: A logical value indicating whether graphics output should be
          produced.

      vp: A Grid viewport object (or NULL)

_D_e_t_a_i_l_s:

     Both functions create a segments grob (a graphical object
     describing segments), but only 'grid.segments' draws the segments
     (and then only if 'draw' is 'TRUE').

_V_a_l_u_e:

     A segments grob.  'grid.segments' returns the value invisibly.

_A_u_t_h_o_r(_s):

     Paul Murrell

_S_e_e _A_l_s_o:

     Grid, 'viewport', 'arrow'

