... Gray-scaling codes the masses of the ob jects (black, gray and white stars: the ob jects at r(g) , g = 1, 2, 3, respectively). x 3 x 3 x 2 x 1 x 2 x 1 Isolines step 0.02 of n lines: negative values, (left to right) x2 = 0, parallel to sides of the ormal ...