Update 4_sommerfeld_model.md

src/4_sommerfeld_model.md

@@ -42,7 +42,7 @@ kcont = np.linspace(-extrapol*kf, extrapol*kf, 1000);
 Edis = ks**2;
 Econt = kcont**2;
 
-fig = plt.figure();
+fig = pyplot.figure();
 ax = fig.add_subplot(111);
 ax.plot(kcont, Econt, 'b-');
 ax.plot(ks, Edis, 'k.');