% Plot f(x,y) = 2*(x-1)^2 + (y-1)^2 on -4 < x < 4, -4 < y < 4

x = linspace(-4,4,30);     % create 1d gridpoints on x and y axes
y = linspace(-4,4,30);

[X,Y] = meshgrid(x,y);     % create 2d mesh of gridpoints over x,y

F = 2*(X-1).^2 + (Y-1).^2; % evaluate the function f(x,y) over mesh

pcolor(x,y,F);             % or contour(X,Y,F), surf(x,y,F), etc. 
colorbar()                 % plot a colorbar

xlabel('x');
ylabel('y');
title('f(x,y) = 2(x-1)^2 + (y-1)^2')

shading interp   % or faceted, flat