that is such a nice way! Thank you very very much! :)

that is such a nice way! Thank you very very much! :)

thanks alec. but if I have a complicated example, as following: implicitplot([2*R^3-R^2+5*R^2*q+4*R*q^2+q^3=0,q^3+3*R*q^2-R^2+3*R^2*q+R^3=0,R^2+2*R^3+3*R^2*q-q^3=0,q^2+R=.3],R=0..2,q=0..1,color=[red,green,blue,black]); I am tring to fill the region right to the black line with horizontal lines, and the region between blue and green lines with vertical lines, then I find the region with grids(overlapped by the two conditions) are what I expect. Could you please to help me about that? Thanks a lot!

thanks alec. but if I have a complicated example, as following: implicitplot([2*R^3-R^2+5*R^2*q+4*R*q^2+q^3=0,q^3+3*R*q^2-R^2+3*R^2*q+R^3=0,R^2+2*R^3+3*R^2*q-q^3=0,q^2+R=.3],R=0..2,q=0..1,color=[red,green,blue,black]); I am tring to fill the region right to the black line with horizontal lines, and the region between blue and green lines with vertical lines, then I find the region with grids(overlapped by the two conditions) are what I expect. Could you please to help me about that? Thanks a lot!