function shape = soma_shape ( index )

  shape_table = { ...
    [ 0,  1,  3 ], ...
    [ 0,  1,  2,  3 ], ...
    [ 0,  1,  2,  4 ], ...
    [ 0,  1,  4,  5 ], ...
    [ 0,  1,  3, 12 ], ...
    [ 0,  1,  3, 10 ], ...
    [ 0,  1,  3,  9 ] };

  shape = shape_table { index };

  return
end

