d = load('-ascii', 'tiempos.log')
x = [ d(:,1:1)' ]
cpp = [ d(:,2:2)' ]
py = [ d(:,3:3)' ]

plot(x, cpp,'1;C++;' , x, py, '2;Python;')
xlabel('log(numero de nodos)')
ylabel('segundos')
title('C++ vs Python')
plot(x, cpp,'1;C++;' , x, py, '2;Python;')

print -dpng performance.png