% Tutorial for CSC336
display('tutorial');
for i=1:2:10
    display(['tutorial: ' num2str(i)]);
end

% assignment statement
a = 100 + (32-17)*5 + 2^3;
% assignment statement - display
a = 100 + (32-17)*5 + 2^3

% logical tests
1<2
2>3
1<=3

if (1<2)
  display('1<2');
end

A = [1 2 3; 4 5 6; 7 8 9];
x = [5 6 7]';
b = A * x;
B = [1 2 3; 3 1 2; 4 2 3;];
% solve linear system By=x;
y = B\x;
% do division
A/B


r = rand(1, 10);
handle = figure(10);
plot(r, 'ob');
r = rand(1, 10);
hold on;
plot(r, 'xr');
hold off;
saveas(gcf, 'tutorial.png', 'png');

figure(11);
x1 = 1:5;
y1 = [10 100 1000 10000 1e5];
semilogy(x1, y1);

n = 10;
e = ones(n^2, 1);
S = spdiags([-e -e 4*e -e -e], [-n -1 0 1 n], n^2, n^2);
figure(12)
spy(S)

[ret1, ret2] = tutorial_fun(A, B);
ret1
ret2