Velocity profiles covered by the mask (yellow shaded area), accompanied by two examples of velocity profiles (orange and blue lines). The two examples are a subset of all the velocity profiles that fit inside the yellow shaded area and thereby are represented by the mask. The horizontal axis shows the distance to the galaxy center r and the vertical axis displays the orbital speed v_R. We note that r is a normalized value between 0 and 1, where 0 is the galaxy center and 1 is the edge.