clc;

x=0:20:500;
y=0:38:950;
[xx,yy]=meshgrid(x,y);

zz1=(sin(0.01*xx)).^3-(cos(0.005*yy)).^3+30.;
surf(x,y,zz1)
hold on

zz2=4.*(cos(0.002*xx)).^3-1.4*(cos(0.01*xx.^5*yy)).^3+10; 
surf(x,y,zz2)
hold on

zz3=5*(sin(xx*yy*yy/2500.)).^3;
surf(x,y,zz3)
hold on

zz4=-20+(0.0*xx);
surf(x,y,zz4)

hold on

title('The picture of the soil');
xlabel('x');
ylabel('y');
drawnow;

hold off

%print -Ppeecs

Q1 = int(int('(sin(0.01*x))^3-(cos(0.005*y))^3+30',0,500),0.001,950);
Q2 = quad('fill_clay2',0,950);
Q3 = int(int('5*(sin(x*y*y/2500.))^3','x',0,500),0.001,950);

Q1
Q2
Q3