
close all
[x,y]=meshgrid(0:0.02:1,-2:0.02:2);


f=x.^2+y.^2;
surf(f)
figure
surf(x,y,f)
contour(f,3)
contour(x,y,f,3)
contour(x,y,f,[0 1 2])
contour(x,y,f,[0 1 2 3 4 5])
hold on
contour(x,y,f,[3/2 5/2],'--')




f1=sin(x.^2)+cos(y.^2) ;
figure
surf(x,y,f1)

contour(x,y,f1)

f2=(x.^3+5)./(y.^2+1) ;
figure
surf(x,y,f2)
figure
contour(x,y,f2)