

_M_e_a_s_u_r_e_m_e_n_t_s _o_n _P_e_t_r_o_l_e_u_m _R_o_c_k _S_a_m_p_l_e_s

     data(rock)

_F_o_r_m_a_t:

     A data frame with 48 rows and 4 numeric columns.

      [,1]     area      area of pores space, in pixels out of 256 by 256
      [,2]     peri      perimeter in pixels
      [,3]     shape     perimeter/sqrt(area)
      [,4]     perm      permeability in milli-Darcies

_D_e_t_a_i_l_s:

     Twelve core samples from petroleum reservoirs were sam-
     pled by 4 cross-sections.  Each core sample was meas-
     ured for permeability, and each cross-section has total
     area of pores, total perimeter of pores, and shape.

_S_o_u_r_c_e:

     Data from BP Research, image analysis by Ronit Katz, U.
     Oxford.

