cleans up error plot

TurTLE/test/test_particle_integration.py

@@ -15,8 +15,9 @@ def main():
 
     data_file = h5py.File(c.simname + '_particles.h5', 'r')
 
-    vv = data_file['particle_o2_n1_m1_f1/velocity/0'][()]
-    print(np.min(vv), np.max(vv))
+    # to figure out reasonable timestep to satisfy "particle shall not move more than one grid cell"
+    #vv = data_file['particle_o2_n1_m1_f1/velocity/0'][()]
+    #print(np.min(vv), np.max(vv))
 
 
     f = plt.figure(figsize = (9, 9))
@@ -43,20 +44,36 @@ def main():
             for factor in [1, 2, 4]:
                 xx1 = data_file['particle_o{0}_n{1}_m{2}_f{3}/position/{4}'.format(oo, n, m, factor, factor*8)][()]
                 xx2 = data_file['particle_o{0}_n{1}_m{2}_f{3}/position/{4}'.format(oo, n, m, factor*2, factor*16)][()]
-                err_list.append(np.mean(np.abs(xx2 - xx1)))
+                diff = np.sqrt(np.sum((xx2 - xx1)**2, axis = -1))
+                err_list.append(np.mean(diff))
             a.plot(dtlist,
                err_list,
                label = 'o{0}_n{1}_m{2}'.format(oo, n, m),
+               dashes = (oo, oo),
                marker = '.')
     a.plot(dtlist,
            np.array(dtlist)**2 * (1e-2),
            color = (0, 0, 0),
-           dashes = (2, 2))
-    a.legend(loc = 'best')
+           dashes = (1, 1),
+           label = '$\\propto \\Delta t^2$')
+    a.plot(dtlist,
+           np.array(dtlist)**3 * (1e-2),
+           color = (0, 0, 0),
+           dashes = (2, 1, 2),
+           label = '$\\propto \\Delta t^3$')
+    a.plot(dtlist,
+           np.array(dtlist)**4 * (1e-2),
+           color = (0, 0, 0),
+           dashes = (3, 5, 3),
+           label = '$\\propto \\Delta t^4$')
+    a.legend(loc = 'upper left')
+    a.set_xlabel('$\\Delta t$')
+    a.set_ylabel('mean trajectory error')
     a.set_xscale('log')
     a.set_yscale('log')
     f.tight_layout()
     f.savefig('test_particle_integration_evdt.pdf')
+    f.savefig('test_particle_integration_evdt.svg')
     plt.close(f)
 
     #f = plt.figure(figsize = (6, 6))