If gener is TRUE, the generalized curve is plotted. Else, the
ordinary curve is plotted.
xlab
Title for the x-axis.
ylab
Title for the y-axis.
add
If add is TRUE, only the curve is drawn. The device must contain
a high-level plot.
grid
If grid >0, a grid is drawn, with spacing equal to 1/grid.
...
Further arguments to be used for drawing the Lorenz curve
(see lines).
References
Cowell F.A. (2000) Measurement of Inequality. In Atkinson A.B., Bourguignon F.
(Eds.) Handbook of Income Distribution. Amsterdam, Elsevier,
Vol. 1, pp. 87-166.