MATLAB

% Matrices and linear algebra
A = [4 -2; 1 1]
x = A \ [2; 3]
[V, D] = eig([2 1; 1 3]);
diag(D)'

A =

     4    -2
     1     1

x =

    1.3333
    1.6667


ans =

    1.3820    3.6180

% A function defined in a cell is there for the cells after it
function y = collatz(n)
  y = n;
  while n ~= 1
    if mod(n, 2) == 0, n = n / 2; else, n = 3 * n + 1; end
    y(end + 1) = n;
  end
end

c = collatz(27);
fprintf('%d steps, peak %d\n', numel(c) - 1, max(c))

111 steps, peak 9232

% Structs and cell arrays
s = struct('name', {'Ada', 'Emmy'}, 'born', {1815, 1882});
for k = 1:numel(s)
  fprintf('%s was born in %d\n', s(k).name, s(k).born);
end
names = upper({s.name})

Ada was born in 1815
Emmy was born in 1882

names =

  1×2 cell array

    {'ADA'}    {'EMMY'}

% Figures
x = linspace(0, 2*pi, 200);
plot(x, sin(x), x, cos(x), '--')
legend('sin', 'cos'); title('Figures show when the cell ends'); grid on

% Surfaces in 3-D
[X, Y, Z] = peaks(40);
surf(X, Y, Z)
colorbar