Solutions lecture 7

src/7_tight_binding_model_sol.md

@@ -34,11 +34,11 @@ Group velocity is given as $v=\hbar^{-1}\frac{\partial E}{\partial k}$ with $E=\
 3.
 
 ```python
-pyplot.figure()
 pyplot.subplot(1,2,1)
 k = np.linspace(-pi/2, pi/2, 300)
-pyplot.plot(k, np.cos(k))
-pyplot.xlabel('$k$'); pyplot.ylabel('$v(k)$')
+ax = pyplot.figure()
+ax.plot(k, np.cos(k))
+ax.xlabel('$k$'); pyplot.ylabel('$v(k)$')
 pyplot.xticks([-pi/2, 0, pi/2], [r'$-\pi/2$', 0, r'$\pi/2$'])
 pyplot.yticks([0, 1], [0, r'$2\sqrt{\frac{\kappa}{m}}$'])
 pyplot.hlines([1], -pi/2, 0, linestyles='dashed')