clear
x = 200 * rand(1) - 100;
y = 200 * rand(1) - 100;
dx = 0.1;

for i = 1:10
    sused0 = [x, y];
    sused1 = [x, y - dx];
    sused2 = [x + dx, y];
    sused3 = [x + dx, y + dx];
    sused4 = [x, y + dx];
    sused5 = [x - dx, y + dx];
    sused6 = [x - dx, y];
    sused7 = [x - dx, y - dx];
    sused8 = [x, y - dx];


    sused = [sused0; sused1; sused2; sused3; sused4; sused5; sused6; sused7; sused8];

    S = testfn3(sused);
end