trans3d              package:grDevices              R Documentation

_3_D _t_o _2_D _T_r_a_n_s_f_o_r_m_a_t_i_o_n _f_o_r _P_e_r_s_p_e_c_t_i_v_e _P_l_o_t_s

_D_e_s_c_r_i_p_t_i_o_n:

     Projection of 3-dimensional to 2-dimensional points using a 4x4
     viewing transformation matrix.  Mainly for adding to perspective
     plots such as 'persp'.

_U_s_a_g_e:

     trans3d(x,y,z, pmat)

_A_r_g_u_m_e_n_t_s:

 x, y, z: numeric vectors of equal length, specifying points in 3D
          space.

    pmat: a 4 x 4 _viewing transformation matrix_, suitable for
          projecting the 3D coordinates (x,y,z) into the 2D plane using
          homogeneous 4D coordinates (x,y,z,t); such matrices are
          returned by 'persp()'.

_V_a_l_u_e:

     a list with two components 

     x,y: the projected 2d coordinates of the 3d input '(x,y,z)'.

_S_e_e _A_l_s_o:

     'persp'

_E_x_a_m_p_l_e_s:

     ## See  help(persp) {after attaching the 'graphics' package}
     ##      -----------