Merge pull request #65 from danielru/fix/phase_speed_plot

Fix phase speed plots

Author: pancetta

examples/acoustic_1d_imex/plot_dispersion.py

@@ -108,23 +108,24 @@ def findomega(stab_fh):
       sol_dirk = findomega(stab_dirk)
 
       # Now solve for discrete phase 
-      phase[0,i]      = sol_sdc.real
+      phase[0,i]      = sol_sdc.real/k_vec[i]
       amp_factor[0,i] = np.exp(sol_sdc.imag)
-      phase[1,i]      = sol_dirk.real
+      phase[1,i]      = sol_dirk.real/k_vec[i]
       amp_factor[1,i] = np.exp(sol_dirk.imag)
     ###
-    rcParams['figure.figsize'] = 2.5, 2.5
+    rcParams['figure.figsize'] = 1.5, 1.5
     fs = 8
     fig  = plt.figure()
-    plt.plot(k_vec, k_vec*(U_speed+c_speed), '--', color='k', linewidth=1.5, label='Exact')
+    plt.plot(k_vec, (U_speed+c_speed)+np.zeros(np.size(k_vec)), '--', color='k', linewidth=1.5, label='Exact')
     plt.plot(k_vec, phase[0,:], '-', color='b', linewidth=1.5, label='SDC('+str(K)+')')
     plt.plot(k_vec, phase[1,:], '-', color='g', linewidth=1.5, label='DIRK('+str(dirkts.order)+')')
-    plt.xlabel('Wave number', fontsize=fs)
-    plt.ylabel('Phase speed', fontsize=fs)
+    plt.xlabel('Wave number', fontsize=fs, labelpad=0.25)
+    plt.ylabel('Phase speed', fontsize=fs, labelpad=0.5)
     plt.xlim([k_vec[0], k_vec[-1:]])
-    plt.ylim([k_vec[0], k_vec[-1:]])
+    plt.ylim([0.0, 1.1*(U_speed+c_speed)])
     fig.gca().tick_params(axis='both', labelsize=fs)
-    plt.legend(loc='upper left', fontsize=fs, prop={'size':fs})
+    plt.legend(loc='lower left', fontsize=fs, prop={'size':fs})
+    plt.xticks([0, 1, 2, 3], fontsize=fs)
     #plt.show()
     filename = 'sdc-fwsw-disprel-phase-K'+str(K)+'-M'+str(swparams['num_nodes'])+'.pdf'
     plt.gcf().savefig(filename, bbox_inches='tight')
@@ -134,13 +135,14 @@ def findomega(stab_fh):
     plt.plot(k_vec, 1.0+np.zeros(np.size(k_vec)), '--', color='k', linewidth=1.5, label='Exact')
     plt.plot(k_vec, amp_factor[0,:], '-', color='b', linewidth=1.5, label='SDC('+str(K)+')')
     plt.plot(k_vec, amp_factor[1,:], '-', color='g', linewidth=1.5, label='DIRK('+str(dirkts.order)+')')
-    plt.xlabel('Wave number', fontsize=fs)
-    plt.ylabel('Amplification factor', fontsize=fs)
+    plt.xlabel('Wave number', fontsize=fs, labelpad=0.25)
+    plt.ylabel('Amplification factor', fontsize=fs, labelpad=0.5)
     fig.gca().tick_params(axis='both', labelsize=fs)
     plt.xlim([k_vec[0], k_vec[-1:]])
     plt.ylim([k_vec[0], k_vec[-1:]])
     plt.legend(loc='lower left', fontsize=fs, prop={'size':fs})
     plt.gca().set_ylim([0.0, 1.1])
+    plt.xticks([0, 1, 2, 3], fontsize=fs)
     #plt.show()
     filename = 'sdc-fwsw-disprel-ampfac-K'+str(K)+'-M'+str(swparams['num_nodes'])+'.pdf'
     plt.gcf().savefig(filename, bbox_inches='tight')