diff --git a/psydac/feec/multipatch/examples/ppc_test_cases.py b/psydac/feec/multipatch/examples/ppc_test_cases.py
index ddfd6659d..d5e2c6e4a 100644
--- a/psydac/feec/multipatch/examples/ppc_test_cases.py
+++ b/psydac/feec/multipatch/examples/ppc_test_cases.py
@@ -114,10 +114,12 @@ def get_Gaussian_beam2(x_0, y_0, domain=None):
     t = [(x-x0)*cos(theta) - (y - y0) * sin(theta), (x-x0)*sin(theta) + (y-y0) * cos(theta)]
 
     ## Gaussian beam
-    '''Beam inciding from the left, centered and normal to wall:
+    """
+    Beam inciding from the left, centered and normal to wall:
         x: axial normalized distance to the beam's focus
         y: radial normalized distance to the center axis of the beam
-    '''
+    """
+    
     EW0 = 1.0  # amplitude at the waist
     k0 = 2 * pi # free-space wavenumber
 
diff --git a/psydac/feec/multipatch/examples_nc/__init__.py b/psydac/feec/multipatch/examples_nc/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/psydac/feec/multipatch/examples_nc/hcurl_eigen_pbms_dg.py b/psydac/feec/multipatch/examples_nc/hcurl_eigen_pbms_dg.py
index 682ff3226..0fba6297d 100644
--- a/psydac/feec/multipatch/examples_nc/hcurl_eigen_pbms_dg.py
+++ b/psydac/feec/multipatch/examples_nc/hcurl_eigen_pbms_dg.py
@@ -30,8 +30,8 @@
 from psydac.feec.multipatch.non_matching_multipatch_domain_utilities import create_square_domain
 from psydac.api.postprocessing import OutputManager, PostProcessManager
 
-def hcurl_solve_eigen_pbm_dg(ncells=[[2,2], [2,2]], degree=[3,3], domain=[[0, np.pi],[0, np.pi]], domain_name='refined_square', backend_language='pyccel-gcc', mu=1, nu=0, gamma_h=0,
-                          generalized_pbm=False, sigma=None, ref_sigmas=[], nb_eigs_solve=8, nb_eigs_plot=5, skip_eigs_threshold=1e-7,
+def hcurl_solve_eigen_pbm_dg(ncells=np.array([[8, 4], [4, 4]]), degree=(3,3), domain=([0, np.pi],[0, np.pi]), domain_name='refined_square', backend_language='pyccel-gcc', mu=1, nu=0, gamma_h=0,
+                          generalized_pbm=False, sigma=5, ref_sigmas=None, nb_eigs_solve=8, nb_eigs_plot=5, skip_eigs_threshold=1e-7,
                           plot_dir=None, hide_plots=True, m_load_dir="",):
 
     diags = {}
diff --git a/psydac/feec/multipatch/examples_nc/hcurl_eigen_pbms_nc.py b/psydac/feec/multipatch/examples_nc/hcurl_eigen_pbms_nc.py
index a99d601a2..77d7b1db9 100644
--- a/psydac/feec/multipatch/examples_nc/hcurl_eigen_pbms_nc.py
+++ b/psydac/feec/multipatch/examples_nc/hcurl_eigen_pbms_nc.py
@@ -33,8 +33,8 @@
 from psydac.api.postprocessing import OutputManager, PostProcessManager
 
 
-def hcurl_solve_eigen_pbm_nc(ncells=[[2,2], [2,2]], degree=[3,3], domain=[[0, np.pi],[0, np.pi]], domain_name='refined_square', backend_language='pyccel-gcc', mu=1, nu=0, gamma_h=0,
-                          generalized_pbm=False, sigma=None, ref_sigmas=[], nb_eigs_solve=8, nb_eigs_plot=5, skip_eigs_threshold=1e-7,
+def hcurl_solve_eigen_pbm_nc(ncells=np.array([[8, 4], [4, 4]]), degree=(3,3), domain=([0, np.pi],[0, np.pi]), domain_name='refined_square', backend_language='pyccel-gcc', mu=1, nu=0, gamma_h=0,
+                          generalized_pbm=False, sigma=5, ref_sigmas=None, nb_eigs_solve=8, nb_eigs_plot=5, skip_eigs_threshold=1e-7,
                           plot_dir=None, hide_plots=True, m_load_dir=None,):
 
     diags = {}
diff --git a/psydac/feec/multipatch/examples_nc/hcurl_eigen_testcase.py b/psydac/feec/multipatch/examples_nc/hcurl_eigen_testcase.py
index 853d33816..6b9c81278 100644
--- a/psydac/feec/multipatch/examples_nc/hcurl_eigen_testcase.py
+++ b/psydac/feec/multipatch/examples_nc/hcurl_eigen_testcase.py
@@ -180,7 +180,12 @@
         nb_eigs_solve = 10 
         nb_eigs_plot = 5 
         skip_eigs_threshold = 1e-7
-
+else:
+    ref_sigmas = None
+    sigma = None
+    nb_eigs_solve = None 
+    nb_eigs_plot = None
+    skip_eigs_threshold = None
 #
 # ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- 
 
@@ -270,7 +275,9 @@
     hide_plots=True,
     m_load_dir=m_load_dir,
     )
-
+else:
+    diags = None
+    eigenvalues = None
 
 if ref_sigmas is not None:
         errors = []
diff --git a/psydac/feec/multipatch/examples_nc/timedomain_maxwell_nc.py b/psydac/feec/multipatch/examples_nc/timedomain_maxwell_nc.py
index fb662b54c..b303f8954 100644
--- a/psydac/feec/multipatch/examples_nc/timedomain_maxwell_nc.py
+++ b/psydac/feec/multipatch/examples_nc/timedomain_maxwell_nc.py
@@ -494,6 +494,9 @@ def source_enveloppe(tau):
             # use source enveloppe for smooth transition from 0 to 1
             def source_enveloppe(tau):        
                 return (special.erf((tau/25)-2)-special.erf(-2))/2
+        else:
+            def source_enveloppe(tau):        
+                return 1
 
     t_stamp = time_count(t_stamp)
     tilde_f0_c = f0_c = None
diff --git a/psydac/feec/multipatch/utils_conga_2d.py b/psydac/feec/multipatch/utils_conga_2d.py
index 8be53b4f8..23046ed32 100644
--- a/psydac/feec/multipatch/utils_conga_2d.py
+++ b/psydac/feec/multipatch/utils_conga_2d.py
@@ -192,7 +192,7 @@ def get_Vh_diags_for(v=None, v_ref=None, M_m=None, print_diags=True, msg='error
     return diags
 
 
-def write_diags_to_file(diags, script_filename, diag_filename, params={}):
+def write_diags_to_file(diags, script_filename, diag_filename, params=None):
     print(' -- writing diags to file {} --'.format(diag_filename))
     if not os.path.exists(diag_filename):
         open(diag_filename, 'w')