[x,y,z]=peaks(75);
figure(1),clf
subplot(2,1,1)
contour(z);
axis([0 80 0 80])
subplot(2,1,2)
contourf(z);
axis([0 80 0 80])
disp('contour(z)');
input('press enter');

figure(1),clf
subplot(2,1,1)
contour(x,y,z);
axis([-3 3 -3 3])
subplot(2,1,2)
contourf(x,y,z);
axis([-3 3 -3 3])
disp('contour(x,y,z)');
input('press enter');

figure(1),clf
subplot(2,1,1)
contour(x,y,z,16);
axis([-3 3 -3 3])
subplot(2,1,2)
contourf(x,y,z,16);
axis([-3 3 -3 3])
disp('contour(x,y,z,16)');
input('press enter');

figure(1),clf
subplot(2,1,1)
contour(x,y,z,[0 0]);
axis([-3 3 -3 3])
subplot(2,1,2)
contourf(x,y,z,[0 0]);
axis([-3 3 -3 3])
disp('contour(x,y,z,[0 0])');
input('press enter');

figure(1),clf
subplot(2,1,1)
contour(x,y,z,[0 1],'EdgeColor','c');
axis([-3 3 -3 3])
subplot(2,1,2)
contourf(x,y,z,[0 1],'EdgeColor','c');
axis([-3 3 -3 3])
disp("contour(x,y,z,\'EdgeColor\',\'c\');")
input('press enter');

figure(1),clf
subplot(2,1,1)
contour(z,[0 1],'EdgeColor','c');
axis([0 80 0 80])
subplot(2,1,2)
contourf(z,[0 1],'EdgeColor','c');
axis([0 80 0 80])
disp("contour(z,[0 1],\'EdgeColor\',\'c\');")
input('press enter');

figure(1),clf
subplot(2,1,1)
contour(z,'EdgeColor','m');
axis([0 80 0 80])
subplot(2,1,2)
contourf(z,'EdgeColor','m');
axis([0 80 0 80])
disp("contour(z,\'EdgeColor\',\'m\');")
input('press enter');

figure(1),clf
subplot(2,1,1)
contour(z,16,'EdgeColor','k');
axis([0 80 0 80])
subplot(2,1,2);
contourf(z,16,'EdgeColor','k');
axis([0 80 0 80])
disp("contour(z,16,\'EdgeColor\',\'k\');")
input('press enter');