arrow                  package:grid                  R Documentation

_D_e_s_c_r_i_b_e _a_r_r_o_w_s _t_o _a_d_d _t_o _a _l_i_n_e.

_D_e_s_c_r_i_p_t_i_o_n:

     Produces a description of what arrows to add to a line. The result
     can be passed to a function that draws a line, e.g., 'grid.lines'.

_U_s_a_g_e:

     arrow(angle = 30, length = unit(0.25, "inches"),
           ends = "last", type = "open")

_A_r_g_u_m_e_n_t_s:

   angle: The angle of the arrow head in degrees (smaller numbers
          produce narrower, pointier arrows).  Essentially describes
          the width of the arrow head.

  length: A unit specifying the length of the arrow head (from tip to
          base).

    ends: One of '"last"', '"first"', or '"both"', indicating which
          ends of the line to draw arrow heads.

    type: One of '"open"' or '"closed"' indicating whether the arrow
          head should be a closed triangle.

_E_x_a_m_p_l_e_s:

     arrow()