diff --git a/examples/cvode_basic.py b/examples/cvode_basic.py
index e453e804..35aeebf6 100644
--- a/examples/cvode_basic.py
+++ b/examples/cvode_basic.py
@@ -66,8 +66,8 @@ def f(t,y):
         pl.show()
     
     #Basic test
-    assert y2[-1][0] == pytest.approx(0.00347746, rel = 1e-5)
-    assert exp_sim.get_last_step() == pytest.approx(0.0222169642893, rel = 1e-3)
+    assert y2[-1][0] == pytest.approx(0.00347746, abs = 1e-5)
+    assert exp_sim.get_last_step() == pytest.approx(0.0222169642893, abs = 1e-3)
     
     return exp_mod, exp_sim
 
diff --git a/examples/cvode_basic_backward.py b/examples/cvode_basic_backward.py
index 4fc55f9f..fc076636 100644
--- a/examples/cvode_basic_backward.py
+++ b/examples/cvode_basic_backward.py
@@ -62,7 +62,7 @@ def f(t,y):
         pl.show()
     
     #Basic test
-    assert y[-1][0] == pytest.approx(4.00000000, rel = 1e-3)
+    assert y[-1][0] == pytest.approx(4.00000000, abs = 1e-3)
     
     return exp_mod, exp_sim
 
diff --git a/examples/cvode_stability.py b/examples/cvode_stability.py
index 706c97c9..346e9745 100644
--- a/examples/cvode_stability.py
+++ b/examples/cvode_stability.py
@@ -89,7 +89,7 @@ def f(t,y):
 
     #Basic test
     x1 = y[:,0]
-    assert_less(np.abs(float(x1[-1]) - 1.8601438), 1e-1)
+    assert np.abs(float(x1[-1]) - 1.8601438) < 1e-1
     
     return exp_mod, exp_sim
 
diff --git a/examples/cvode_with_disc.py b/examples/cvode_with_disc.py
index 96daa656..fec9d8e0 100644
--- a/examples/cvode_with_disc.py
+++ b/examples/cvode_with_disc.py
@@ -156,14 +156,11 @@ def run_example(with_plots=True):
         pl.show()
     
     #Basic test
-    assert_almost_equal(y[-1][0],8.0)
-    assert_almost_equal(y[-1][1],3.0)
-    assert_almost_equal(y[-1][2],2.0)
+    assert y[-1][0] == pytest.approx(8.0)
+    assert y[-1][1] == pytest.approx(3.0)
+    assert y[-1][2] == pytest.approx(2.0)
     
     return exp_mod, exp_sim
     
 if __name__=="__main__":
     mod,sim = run_example()
-    
-
-    
diff --git a/examples/cvode_with_initial_sensitivity.py b/examples/cvode_with_initial_sensitivity.py
index 4110fba5..ed1707e3 100644
--- a/examples/cvode_with_initial_sensitivity.py
+++ b/examples/cvode_with_initial_sensitivity.py
@@ -123,9 +123,9 @@ def f(t, y, p):
         pl.show()
     
     #Basic test
-    assert y[-1][0] == pytest.approx(1577.6552477, rel = 1e-5)
-    assert y[-1][1] == pytest.approx(611.9574565, rel = 1e-5)
-    assert y[-1][2] == pytest.approx(2215.88563217, rel = 1e-5)
+    assert y[-1][0] == pytest.approx(1577.6552477, abs = 1e-5)
+    assert y[-1][1] == pytest.approx(611.9574565, abs = 1e-5)
+    assert y[-1][2] == pytest.approx(2215.88563217, abs = 1e-5)
     assert exp_sim.p_sol[0][1][0] == pytest.approx(1.0)
     
     return exp_mod, exp_sim
diff --git a/examples/cvode_with_jac.py b/examples/cvode_with_jac.py
index f8885dd3..d5b02e74 100644
--- a/examples/cvode_with_jac.py
+++ b/examples/cvode_with_jac.py
@@ -78,8 +78,8 @@ def jac(t,y):
         pl.show()
     
     #Basic tests
-    assert_almost_equal(y[-1][0],-121.75000000,4)
-    assert_almost_equal(y[-1][1],-49.100000000)
+    assert y[-1][0] == pytest.approx(-121.75000000, abs = 1e-4)
+    assert y[-1][1] == pytest.approx(-49.100000000)
     
     return exp_mod, exp_sim
 
diff --git a/examples/cvode_with_jac_sparse.py b/examples/cvode_with_jac_sparse.py
index fc77f31e..7ee70260 100644
--- a/examples/cvode_with_jac_sparse.py
+++ b/examples/cvode_with_jac_sparse.py
@@ -93,7 +93,7 @@ def jac(t,y):
         pl.show()
     
     #Basic tests
-    assert_almost_equal(y[-1][0],0.9851,3)
+    assert y[-1][0] == pytest.approx(0.9851, abs = 1e-3)
     
     return exp_mod, exp_sim
 
diff --git a/examples/cvode_with_jac_spgmr.py b/examples/cvode_with_jac_spgmr.py
index b797ecb8..d1ace07b 100644
--- a/examples/cvode_with_jac_spgmr.py
+++ b/examples/cvode_with_jac_spgmr.py
@@ -85,8 +85,8 @@ def jacv(t,y,fy,v):
         pl.show()
     
     #Basic tests
-    assert_almost_equal(y[-1][0],-121.75000000,4)
-    assert_almost_equal(y[-1][1],-49.100000000)
+    assert y[-1][0] == pytest.approx(-121.75000000, abs = 1e-4)
+    assert y[-1][1] == pytest.approx(-49.100000000)
     
     return exp_mod, exp_sim
 
diff --git a/examples/cvode_with_parameters.py b/examples/cvode_with_parameters.py
index 021c1959..c7906c9c 100644
--- a/examples/cvode_with_parameters.py
+++ b/examples/cvode_with_parameters.py
@@ -87,12 +87,12 @@ def f(t, y, p):
         pl.show()  
     
     #Basic test
-    assert y[-1][0] == pytest.approx(9.05518032e-01, rel = 1e-4)
-    assert y[-1][1] == pytest.approx(2.24046805e-05, rel = 1e-4)
-    assert y[-1][2] == pytest.approx(9.44595637e-02, rel = 1e-4)
-    assert exp_sim.p_sol[0][-1][0] == pytest.approx(-1.8761, rel = 1e-2) #Values taken from the example in Sundials
-    assert exp_sim.p_sol[1][-1][0] == pytest.approx(2.9614e-06, rel = 1e-8)
-    assert exp_sim.p_sol[2][-1][0] == pytest.approx(-4.9334e-10, rel = 1e-12)
+    assert y[-1][0] == pytest.approx(9.05518032e-01, abs = 1e-4)
+    assert y[-1][1] == pytest.approx(2.24046805e-05, abs = 1e-4)
+    assert y[-1][2] == pytest.approx(9.44595637e-02, abs = 1e-4)
+    assert exp_sim.p_sol[0][-1][0] == pytest.approx(-1.8761, abs = 1e-2) #Values taken from the example in Sundials
+    assert exp_sim.p_sol[1][-1][0] == pytest.approx(2.9614e-06, abs = 1e-8)
+    assert exp_sim.p_sol[2][-1][0] == pytest.approx(-4.9334e-10, abs = 1e-12)
     
     return exp_mod, exp_sim
 
diff --git a/examples/cvode_with_parameters_fcn.py b/examples/cvode_with_parameters_fcn.py
index 62389c95..646ee55e 100644
--- a/examples/cvode_with_parameters_fcn.py
+++ b/examples/cvode_with_parameters_fcn.py
@@ -104,12 +104,12 @@ def fsens(t, y, s, p):
         pl.show()  
     
     #Basic test
-    assert y[-1][0] == pytest.approx(9.05518032e-01, rel = 1e-4)
-    assert y[-1][1] == pytest.approx(2.24046805e-05, rel = 1e-4)
-    assert y[-1][2] == pytest.approx(9.44595637e-02, rel = 1e-4)
-    assert exp_sim.p_sol[0][-1][0] == pytest.approx(-1.8761, rel = 1e-2) #Values taken from the example in Sundials
-    assert exp_sim.p_sol[1][-1][0] == pytest.approx(2.9614e-06, rel = 1e-8)
-    assert exp_sim.p_sol[2][-1][0] == pytest.approx(-4.9334e-10, rel = 1e-12)
+    assert y[-1][0] == pytest.approx(9.05518032e-01, abs = 1e-4)
+    assert y[-1][1] == pytest.approx(2.24046805e-05, abs = 1e-4)
+    assert y[-1][2] == pytest.approx(9.44595637e-02, abs = 1e-4)
+    assert exp_sim.p_sol[0][-1][0] == pytest.approx(-1.8761, abs = 1e-2) #Values taken from the example in Sundials
+    assert exp_sim.p_sol[1][-1][0] == pytest.approx(2.9614e-06, abs = 1e-8)
+    assert exp_sim.p_sol[2][-1][0] == pytest.approx(-4.9334e-10, abs = 1e-12)
         
     return exp_mod, exp_sim
 
diff --git a/examples/cvode_with_parameters_modified.py b/examples/cvode_with_parameters_modified.py
index 94624a87..8bd28f42 100644
--- a/examples/cvode_with_parameters_modified.py
+++ b/examples/cvode_with_parameters_modified.py
@@ -85,11 +85,11 @@ def f(t, y, p):
         pl.show()  
     
     #Basic test
-    assert y[-1][0] == pytest.approx(9.05518032e-01, rel = 1e-4)
-    assert y[-1][1] == pytest.approx(2.24046805e-05, rel = 1e-4)
-    assert y[-1][2] == pytest.approx(9.44595637e-02, rel = 1e-4)
-    assert exp_sim.p_sol[0][-1][0] == pytest.approx(-1.8761, rel = 1e-2) #Values taken from the example in Sundials
-    assert exp_sim.p_sol[1][-1][0] == pytest.approx(2.9614e-06, rel = 1e-8)
+    assert y[-1][0] == pytest.approx(9.05518032e-01, abs = 1e-4)
+    assert y[-1][1] == pytest.approx(2.24046805e-05, abs = 1e-4)
+    assert y[-1][2] == pytest.approx(9.44595637e-02, abs = 1e-4)
+    assert exp_sim.p_sol[0][-1][0] == pytest.approx(-1.8761, abs = 1e-2) #Values taken from the example in Sundials
+    assert exp_sim.p_sol[1][-1][0] == pytest.approx(2.9614e-06, abs = 1e-8)
     
     return exp_mod, exp_sim
 
diff --git a/examples/cvode_with_preconditioning.py b/examples/cvode_with_preconditioning.py
index 4d965727..84e34291 100644
--- a/examples/cvode_with_preconditioning.py
+++ b/examples/cvode_with_preconditioning.py
@@ -107,8 +107,8 @@ def prec_solve(t, y, fy, r, gamma, delta, data):
         exp_sim.plot()
     
     #Basic verification
-    assert_almost_equal(y[-1,0],3.11178295,4)
-    assert_almost_equal(y[-1,1],3.19318992,4)
+    assert y[-1,0] == pytest.approx(3.11178295, abs = 1e-4)
+    assert y[-1,1] == pytest.approx(3.19318992, abs = 1e-4)
 
     return exp_mod, exp_sim
     
diff --git a/examples/dasp3_basic.py b/examples/dasp3_basic.py
index a7a13934..ef78c244 100644
--- a/examples/dasp3_basic.py
+++ b/examples/dasp3_basic.py
@@ -100,7 +100,7 @@ def dzdt(t,y,z):
         pl.show()
     
     #Basic test
-    assert_almost_equal(y[-1,0], 10.860063849896818, 3)
+    assert y[-1,0] == pytest.approx( 10.860063849896818, abs = 1e-3)
     
     return exp_mod, exp_sim
 
diff --git a/examples/dopri5_basic.py b/examples/dopri5_basic.py
index 393b9427..36a83e67 100644
--- a/examples/dopri5_basic.py
+++ b/examples/dopri5_basic.py
@@ -56,7 +56,7 @@ def f(t,y):
         pl.show()
     
     #Basic test
-    assert_almost_equal(y[-1][0],0.02695199,5)
+    assert y[-1][0] == pytest.approx(0.02695199, abs = 1e-5)
     
     return exp_mod, exp_sim
 
diff --git a/examples/dopri5_with_disc.py b/examples/dopri5_with_disc.py
index 2c4ce9c5..92aa2002 100644
--- a/examples/dopri5_with_disc.py
+++ b/examples/dopri5_with_disc.py
@@ -155,9 +155,9 @@ def run_example(with_plots=True):
         pl.show()
         
     #Basic test
-    assert_almost_equal(y[-1][0],8.0)
-    assert_almost_equal(y[-1][1],3.0)
-    assert_almost_equal(y[-1][2],2.0)
+    assert y[-1][0] == pytest.approx(8.0)
+    assert y[-1][1] == pytest.approx(3.0)
+    assert y[-1][2] == pytest.approx(2.0)
     
     return exp_mod, exp_sim
     
diff --git a/examples/euler_vanderpol.py b/examples/euler_vanderpol.py
index 45af37bc..f4dc7109 100644
--- a/examples/euler_vanderpol.py
+++ b/examples/euler_vanderpol.py
@@ -86,7 +86,7 @@ def jac(t,y):
 
     #Basic test
     x1 = y[:,0]
-    assert_less(np.abs(float(x1[-1]) - 1.8601438), 1e-1)
+    assert np.abs(float(x1[-1]) - 1.8601438) < 1e-1
     
     return exp_mod, exp_sim
 
diff --git a/examples/euler_with_disc.py b/examples/euler_with_disc.py
index ecc7d3aa..3fcdb3c3 100644
--- a/examples/euler_with_disc.py
+++ b/examples/euler_with_disc.py
@@ -152,9 +152,9 @@ def run_example(with_plots=True):
         pl.show()
     
     #Basic test
-    assert_almost_equal(y[-1][0],8.0)
-    assert_almost_equal(y[-1][1],3.0)
-    assert_almost_equal(y[-1][2],2.0)
+    assert y[-1][0] == pytest.approx(8.0)
+    assert y[-1][1] == pytest.approx(3.0)
+    assert y[-1][2] == pytest.approx(2.0)
     
     return exp_mod, exp_sim
         
diff --git a/examples/glimda_vanderpol.py b/examples/glimda_vanderpol.py
index 993b71d3..8cc75939 100644
--- a/examples/glimda_vanderpol.py
+++ b/examples/glimda_vanderpol.py
@@ -86,7 +86,7 @@ def f(t,y,yd):
     
     #Basic test
     x1 = y[:,0]
-    assert float(x1[-1]) == pytest.approx(1.706168035, rel = 1e-3)
+    assert float(x1[-1]) == pytest.approx(1.706168035, abs = 1e-3)
     
     return imp_mod, imp_sim
 
diff --git a/examples/ida_basic_backward.py b/examples/ida_basic_backward.py
index fd6913bf..1ca05e37 100644
--- a/examples/ida_basic_backward.py
+++ b/examples/ida_basic_backward.py
@@ -62,7 +62,7 @@ def f(t,y,yd):
         pl.show()
     
     #Basic test
-    assert y[-1][0] == pytest.approx(4.00000000, rel = 1e-3)
+    assert y[-1][0] == pytest.approx(4.00000000, abs = 1e-3)
     
     return imp_mod, imp_sim
 
diff --git a/examples/ida_with_disc.py b/examples/ida_with_disc.py
index 9d0a3b6f..1b2ce144 100644
--- a/examples/ida_with_disc.py
+++ b/examples/ida_with_disc.py
@@ -158,9 +158,9 @@ def run_example(with_plots=True):
         pl.show()
     
     #Basic test
-    assert_almost_equal(y[-1][0],8.0)
-    assert_almost_equal(y[-1][1],3.0)
-    assert_almost_equal(y[-1][2],2.0)
+    assert y[-1][0] == pytest.approx(8.0)
+    assert y[-1][1] == pytest.approx(3.0)
+    assert y[-1][2] == pytest.approx(2.0)
     
     return imp_mod, imp_sim
     
diff --git a/examples/ida_with_initial_sensitivity.py b/examples/ida_with_initial_sensitivity.py
index d4bfad0e..7233202c 100644
--- a/examples/ida_with_initial_sensitivity.py
+++ b/examples/ida_with_initial_sensitivity.py
@@ -114,9 +114,9 @@ def f(t, y, yd,p):
         pl.show()
     
     #Basic test
-    assert_almost_equal(y[-1][0], 1577.6552477,3)
-    assert y[-1][1] == pytest.approx(611.9574565, rel = 1e-3)
-    assert y[-1][2] == pytest.approx(2215.88563217, rel = 1e-3)
+    assert y[-1][0] == pytest.approx(1577.6552477, abs = 1e-3)
+    assert y[-1][1] == pytest.approx(611.9574565, abs = 1e-3)
+    assert y[-1][2] == pytest.approx(2215.88563217, abs = 1e-3)
     assert imp_sim.p_sol[0][1][0] == pytest.approx(1.0)
     
         
diff --git a/examples/ida_with_jac.py b/examples/ida_with_jac.py
index a57d70ec..ac26d6a5 100644
--- a/examples/ida_with_jac.py
+++ b/examples/ida_with_jac.py
@@ -98,7 +98,7 @@ def jac(c,t,y,yd):
     #Sets the parameters
     imp_sim.atol = 1e-6 #Default 1e-6
     imp_sim.rtol = 1e-6 #Default 1e-6
-    imp_sim.suppress_alg = True #Suppres the algebraic variables on the error test
+    imp_sim.suppress_alg = True #Suppress the algebraic variables on the error test
     
     #Let Sundials find consistent initial conditions by use of 'IDA_YA_YDP_INIT'
     imp_sim.make_consistent('IDA_YA_YDP_INIT')
@@ -107,10 +107,10 @@ def jac(c,t,y,yd):
     t, y, yd = imp_sim.simulate(5,1000) #Simulate 5 seconds with 1000 communication points
     
     #Basic tests
-    assert_almost_equal(y[-1][0],0.9401995, places=4)
-    assert_almost_equal(y[-1][1],-0.34095124, places=4)
-    assert yd[-1][0] == pytest.approx(-0.88198927, rel = 1e-4)
-    assert yd[-1][1] == pytest.approx(-2.43227069, rel = 1e-4)
+    assert y[-1][0] == pytest.approx(0.9401995, abs = 1e-4)
+    assert y[-1][1] == pytest.approx(-0.34095124, abs = 1e-4)
+    assert yd[-1][0] == pytest.approx(-0.88198927, abs = 1e-4)
+    assert yd[-1][1] == pytest.approx(-2.43227069, abs = 1e-4)
     
     #Plot
     if with_plots:
diff --git a/examples/ida_with_jac_spgmr.py b/examples/ida_with_jac_spgmr.py
index 5ae85f0d..fd759e56 100644
--- a/examples/ida_with_jac_spgmr.py
+++ b/examples/ida_with_jac_spgmr.py
@@ -77,8 +77,8 @@ def jacv(t,y,yd,res,v,c):
     t, y, yd = imp_sim.simulate(5, 1000) #Simulate 5 seconds with 1000 communication points
     
     #Basic tests
-    assert_almost_equal(y[-1][0],-121.75000000,4)
-    assert_almost_equal(y[-1][1],-49.100000000)
+    assert y[-1][0] == pytest.approx(-121.75000000, abs = 1e-4)
+    assert y[-1][1] == pytest.approx(-49.100000000)
     
     #Plot
     if with_plots:
diff --git a/examples/ida_with_parameters.py b/examples/ida_with_parameters.py
index 0820ddc6..15a12e9b 100644
--- a/examples/ida_with_parameters.py
+++ b/examples/ida_with_parameters.py
@@ -66,7 +66,7 @@ def f(t, y, yd, p):
     #Sets the parameters
     imp_sim.atol = np.array([1.0e-8, 1.0e-14, 1.0e-6])
     imp_sim.algvar = [1.0,1.0,0.0]
-    imp_sim.suppress_alg = False #Suppres the algebraic variables on the error test
+    imp_sim.suppress_alg = False #Suppress the algebraic variables on the error test
     imp_sim.report_continuously = True #Store data continuous during the simulation
     imp_sim.pbar = p0
     imp_sim.suppress_sens = False            #Dont suppress the sensitivity variables in the error test.
@@ -78,12 +78,12 @@ def f(t, y, yd, p):
     t, y, yd = imp_sim.simulate(4,400) #Simulate 4 seconds with 400 communication points
 
     #Basic test
-    assert y[-1][0] == pytest.approx(9.05518032e-01, rel = 1e-4)
-    assert y[-1][1] == pytest.approx(2.24046805e-05, rel = 1e-4)
-    assert y[-1][2] == pytest.approx(9.44595637e-02, rel = 1e-4)
-    assert imp_sim.p_sol[0][-1][0] == pytest.approx(-1.8761, rel = 1e-2) #Values taken from the example in Sundials
-    assert imp_sim.p_sol[1][-1][0] == pytest.approx(2.9614e-06, rel = 1e-8)
-    assert imp_sim.p_sol[2][-1][0] == pytest.approx(-4.9334e-10, rel = 1e-12)
+    assert y[-1][0] == pytest.approx(9.05518032e-01, abs = 1e-4)
+    assert y[-1][1] == pytest.approx(2.24046805e-05, abs = 1e-4)
+    assert y[-1][2] == pytest.approx(9.44595637e-02, abs = 1e-4)
+    assert imp_sim.p_sol[0][-1][0] == pytest.approx(-1.8761, abs = 1e-2) #Values taken from the example in Sundials
+    assert imp_sim.p_sol[1][-1][0] == pytest.approx(2.9614e-06, abs = 1e-8)
+    assert imp_sim.p_sol[2][-1][0] == pytest.approx(-4.9334e-10, abs = 1e-12)
     
     #Plot
     if with_plots:
diff --git a/examples/ida_with_user_defined_handle_result.py b/examples/ida_with_user_defined_handle_result.py
index 090286ee..9414c412 100644
--- a/examples/ida_with_user_defined_handle_result.py
+++ b/examples/ida_with_user_defined_handle_result.py
@@ -81,7 +81,7 @@ def handle_result(solver, t ,y, yd):
     #Sets the parameters
     imp_sim.atol = 1e-6 #Default 1e-6
     imp_sim.rtol = 1e-6 #Default 1e-6
-    imp_sim.suppress_alg = True #Suppres the algebraic variables on the error test
+    imp_sim.suppress_alg = True #Suppress the algebraic variables on the error test
     imp_sim.report_continuously = True
     
     #Let Sundials find consistent initial conditions by use of 'IDA_YA_YDP_INIT'
@@ -107,11 +107,11 @@ def handle_result(solver, t ,y, yd):
         pl.show()
     
     #Basic tests
-    assert_almost_equal(y[-1][0],0.9401995, places=4)
-    assert_almost_equal(y[-1][1],-0.34095124, places=4)
-    assert yd[-1][0] == pytest.approx(-0.88198927, rel = 1e-4)
-    assert yd[-1][1] == pytest.approx(-2.43227069, rel = 1e-4)
-    assert order[-1] == pytest.approx(5, rel = 1e-4)
+    assert y[-1][0] == pytest.approx(0.9401995, abs = 1e-4)
+    assert y[-1][1] == pytest.approx(-0.34095124, abs = 1e-4)
+    assert yd[-1][0] == pytest.approx(-0.88198927, abs = 1e-4)
+    assert yd[-1][1] == pytest.approx(-2.43227069, abs = 1e-4)
+    assert order[-1] == pytest.approx(5, abs = 1e-4)
     
     return imp_mod, imp_sim
 
diff --git a/examples/kinsol_basic.py b/examples/kinsol_basic.py
index 633d8216..d4af5d37 100644
--- a/examples/kinsol_basic.py
+++ b/examples/kinsol_basic.py
@@ -46,7 +46,7 @@ def res(y):
     y = alg_solver.solve()
     
     #Basic test
-    assert y == pytest.approx(1.0, rel = 1e-5)
+    assert y == pytest.approx(1.0, abs = 1e-5)
     
     return alg_mod, alg_solver
 
diff --git a/examples/kinsol_ors.py b/examples/kinsol_ors.py
index 5e39a9a7..a2c55b06 100644
--- a/examples/kinsol_ors.py
+++ b/examples/kinsol_ors.py
@@ -126,7 +126,7 @@ def setup_param(solver):
     
     #Basic test
     for j in range(len(y)):
-        assert y[j] == pytest.approx(1.0, rel = 1e-4)
+        assert y[j] == pytest.approx(1.0, abs = 1e-4)
         
     return [alg_mod, alg_mod_prec], [alg_solver, alg_solver_prec]
 
diff --git a/examples/kinsol_with_jac.py b/examples/kinsol_with_jac.py
index a6cb725d..235de43c 100644
--- a/examples/kinsol_with_jac.py
+++ b/examples/kinsol_with_jac.py
@@ -51,8 +51,8 @@ def jac(y):
     y = alg_solver.solve()
     
     #Basic test
-    assert y[0] == pytest.approx(1.5, rel = 1e-5)
-    assert y[1] == pytest.approx(1.0, rel = 1e-5)
+    assert y[0] == pytest.approx(1.5, abs = 1e-5)
+    assert y[1] == pytest.approx(1.0, abs = 1e-5)
     
     return alg_mod, alg_solver
     
diff --git a/examples/lsodar_vanderpol.py b/examples/lsodar_vanderpol.py
index 300da948..916a351f 100644
--- a/examples/lsodar_vanderpol.py
+++ b/examples/lsodar_vanderpol.py
@@ -75,7 +75,7 @@ def f(t,y):
     
     #Basic test
     x1 = y[:,0]
-    assert_less(np.abs(x1[-1] - 1.706168035), 1e-3)
+    assert np.abs(x1[-1] - 1.706168035) < 1e-3
     
     return exp_mod, exp_sim
 
diff --git a/examples/lsodar_with_disc.py b/examples/lsodar_with_disc.py
index 398c4008..902f0463 100644
--- a/examples/lsodar_with_disc.py
+++ b/examples/lsodar_with_disc.py
@@ -152,9 +152,9 @@ def run_example(with_plots=True):
         pl.show()
         
     #Basic test
-    assert_almost_equal(y[-1][0],8.0)
-    assert_almost_equal(y[-1][1],3.0)
-    assert_almost_equal(y[-1][2],2.0)
+    assert y[-1][0] == pytest.approx(8.0)
+    assert y[-1][1] == pytest.approx(3.0)
+    assert y[-1][2] == pytest.approx(2.0)
 
     return exp_mod, exp_sim
     
diff --git a/examples/mech_system_pendulum.py b/examples/mech_system_pendulum.py
index cc9a6e79..19805285 100644
--- a/examples/mech_system_pendulum.py
+++ b/examples/mech_system_pendulum.py
@@ -60,7 +60,7 @@ def run_example(index="ind1", with_plots=True, with_test=False):
     print(final_residual, 'Norm:  ', np.linalg.norm(final_residual))
     
     if with_test:
-        assert_less(np.linalg.norm(final_residual), 1.5e-1)
+        assert np.linalg.norm(final_residual) < 1.5e-1
     if with_plots:
         dae_pend.plot(mask=[1,1]+(len(my_pend.y0)-2)*[0]) 
     return my_pend, dae_pend
diff --git a/examples/radau5dae_time_events.py b/examples/radau5dae_time_events.py
index 7e23e215..0780e34b 100644
--- a/examples/radau5dae_time_events.py
+++ b/examples/radau5dae_time_events.py
@@ -73,7 +73,7 @@ def run_example(with_plots=True):
     
     #Basic test
     x1 = y[:,0]
-    assert_less(np.abs(float(x1[-1]) - 1.14330840983), 1e-3)
+    assert np.abs(float(x1[-1]) - 1.14330840983) < 1e-3
 
     return imp_mod, imp_sim
 if __name__=='__main__':
diff --git a/examples/radau5dae_vanderpol.py b/examples/radau5dae_vanderpol.py
index 65e35a59..6dec4d00 100644
--- a/examples/radau5dae_vanderpol.py
+++ b/examples/radau5dae_vanderpol.py
@@ -86,7 +86,7 @@ def f(t,y,yd):
     
     #Basic test
     x1 = y[:,0]
-    assert_less(np.abs(float(x1[-1]) - 1.706168035), 1e-3)
+    assert np.abs(float(x1[-1]) - 1.706168035) < 1e-3
 
     return imp_mod, imp_sim
 
diff --git a/examples/radau5ode_vanderpol.py b/examples/radau5ode_vanderpol.py
index da6f81d4..577b856a 100644
--- a/examples/radau5ode_vanderpol.py
+++ b/examples/radau5ode_vanderpol.py
@@ -76,7 +76,7 @@ def f(t,y):
 
     #Basic test
     x1 = y[:,0]
-    assert_less(np.abs(float(x1[-1]) - 1.706168035), 1e-3)
+    assert np.abs(float(x1[-1]) - 1.706168035) < 1e-3
     
     return exp_mod, exp_sim
 
diff --git a/examples/radau5ode_with_disc.py b/examples/radau5ode_with_disc.py
index 17acc0a9..8311d413 100644
--- a/examples/radau5ode_with_disc.py
+++ b/examples/radau5ode_with_disc.py
@@ -134,9 +134,9 @@ def run_example(with_plots=True):
     t, y = exp_sim.simulate(10.0,1000) #Simulate 10 seconds with 1000 communications points
     
     #Basic test
-    assert_almost_equal(y[-1][0],8.0)
-    assert_almost_equal(y[-1][1],3.0)
-    assert_almost_equal(y[-1][2],2.0)
+    assert y[-1][0] == pytest.approx(8.0)
+    assert y[-1][1] == pytest.approx(3.0)
+    assert y[-1][2] == pytest.approx(2.0)
     
    #Plot
     if with_plots:
diff --git a/examples/radau5ode_with_disc_sparse.py b/examples/radau5ode_with_disc_sparse.py
index c80b55c6..c7b796cc 100644
--- a/examples/radau5ode_with_disc_sparse.py
+++ b/examples/radau5ode_with_disc_sparse.py
@@ -142,9 +142,9 @@ def run_example(with_plots=True):
     t, y = exp_sim.simulate(10.0,1000) #Simulate 10 seconds with 1000 communications points
     
     #Basic test
-    assert_almost_equal(y[-1][0],8.0)
-    assert_almost_equal(y[-1][1],3.0)
-    assert_almost_equal(y[-1][2],2.0)
+    assert y[-1][0] == pytest.approx(8.0)
+    assert y[-1][1] == pytest.approx(3.0)
+    assert y[-1][2] == pytest.approx(2.0)
     
    #Plot
     if with_plots:
diff --git a/examples/radau5ode_with_jac_sparse.py b/examples/radau5ode_with_jac_sparse.py
index 1553ab24..00b99521 100644
--- a/examples/radau5ode_with_jac_sparse.py
+++ b/examples/radau5ode_with_jac_sparse.py
@@ -89,7 +89,7 @@ def jac(t,y):
         pl.show()
     
     #Basic tests
-    assert y[-1][0] == pytest.approx(0.9851, rel = 1e-3)
+    assert y[-1][0] == pytest.approx(0.9851, abs = 1e-3)
     
     return exp_mod, exp_sim
 
diff --git a/examples/rodasode_vanderpol.py b/examples/rodasode_vanderpol.py
index 1abc2533..d1ec8777 100644
--- a/examples/rodasode_vanderpol.py
+++ b/examples/rodasode_vanderpol.py
@@ -86,7 +86,7 @@ def jac(t,y):
     
     #Basic test
     x1 = y[:,0]
-    assert_less(np.abs(float(x1[-1]) - 1.706168035), 1e-3)
+    assert np.abs(float(x1[-1]) - 1.706168035) < 1e-3
 
     return exp_mod, exp_sim
 
diff --git a/examples/rungekutta34_basic.py b/examples/rungekutta34_basic.py
index 3037a451..273e9363 100644
--- a/examples/rungekutta34_basic.py
+++ b/examples/rungekutta34_basic.py
@@ -49,7 +49,7 @@ def f(t,y):
     t, y = exp_sim.simulate(5) #Simulate 5 seconds
     
     #Basic test
-    assert y[-1][0] == pytest.approx(0.02695199, rel = 1e-5)
+    assert y[-1][0] == pytest.approx(0.02695199, abs = 1e-5)
     
     #Plot
     if with_plots:
diff --git a/examples/rungekutta34_with_disc.py b/examples/rungekutta34_with_disc.py
index fe84ea06..9df65b2b 100644
--- a/examples/rungekutta34_with_disc.py
+++ b/examples/rungekutta34_with_disc.py
@@ -136,9 +136,9 @@ def run_example(with_plots=True):
     t, y = exp_sim.simulate(10.0,1000) #Simulate 10 seconds with 1000 communications points
     
     #Basic test
-    assert_almost_equal(y[-1][0],8.0)
-    assert_almost_equal(y[-1][1],3.0)
-    assert_almost_equal(y[-1][2],2.0)
+    assert y[-1][0] == pytest.approx(8.0)
+    assert y[-1][1] == pytest.approx(3.0)
+    assert y[-1][2] == pytest.approx(2.0)
     
     #Plot
     if with_plots:
diff --git a/src/problem.pyx b/src/problem.pyx
index 6e4ebbb3..a394f19f 100644
--- a/src/problem.pyx
+++ b/src/problem.pyx
@@ -166,7 +166,7 @@ cdef class cExplicit_Problem(cProblem):
         return ID_OK
         
     cpdef np.ndarray res(self, t, y, yd, sw=None):
-        if sw == None:
+        if sw is None:
             return yd-self.rhs(t,y)
         else:
             return yd-self.rhs(t, y, sw)
diff --git a/src/solvers/sdirk_dae.pyx b/src/solvers/sdirk_dae.pyx
index f5668503..b4d35ba3 100644
--- a/src/solvers/sdirk_dae.pyx
+++ b/src/solvers/sdirk_dae.pyx
@@ -144,7 +144,7 @@ class SDIRK_DAE(Implicit_ODE):
         #Run in normal mode?
         normal_mode = 1 if opts["output_list"] != None else 0
         #if normal_mode == 0:
-        if opts["report_continuously"] or opts["output_list"] == None:
+        if opts["report_continuously"] or opts["output_list"] is None:
             while (ISTATE == 2 or ISTATE == 1) and t < tf:
             
                 y, t, ISTATE, RWORK, IWORK, roots = dlsodar(self.problem.rhs, y.copy(), t, tf, ITOL, 
diff --git a/tests/solvers/test_euler.py b/tests/solvers/test_euler.py
index 87e1b7c7..0cf2e412 100644
--- a/tests/solvers/test_euler.py
+++ b/tests/solvers/test_euler.py
@@ -119,6 +119,7 @@ def init_mode(self, solver):
 class Test_Explicit_Euler:
     
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This function sets up the test case.
@@ -271,6 +272,7 @@ def f(t, y):
 class Test_Implicit_Euler:
     
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This function sets up the test case.
@@ -306,13 +308,13 @@ def test_usejac_csc_matrix(self):
         exp_sim.simulate(5.,100)
         
         assert exp_sim.statistics["nfcnjacs"] == 0
-        assert exp_sim.y_sol[-1][0] == pytest.approx(-121.995500, rel = 1e-4)
+        assert exp_sim.y_sol[-1][0] == pytest.approx(-121.995500, abs = 1e-4)
         
         exp_sim.reset()
         exp_sim.usejac=False
         exp_sim.simulate(5.,100)
 
-        assert exp_sim.y_sol[-1][0] == pytest.approx(-121.995500, rel = 1e-4)
+        assert exp_sim.y_sol[-1][0] == pytest.approx(-121.995500, abs = 1e-4)
         assert exp_sim.statistics["nfcnjacs"] > 0
     
     @testattr(stddist = True)
diff --git a/tests/solvers/test_glimda.py b/tests/solvers/test_glimda.py
index 59cc28db..c16fc913 100644
--- a/tests/solvers/test_glimda.py
+++ b/tests/solvers/test_glimda.py
@@ -28,6 +28,7 @@ class Test_GLIMDA:
     Tests the GLIMDA solver.
     """
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This sets up the test case.
diff --git a/tests/solvers/test_odassl.py b/tests/solvers/test_odassl.py
index 099c9cce..82a76d4c 100644
--- a/tests/solvers/test_odassl.py
+++ b/tests/solvers/test_odassl.py
@@ -25,6 +25,7 @@
 class Test_ODASSL:
     
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This function sets up the test case.
diff --git a/tests/solvers/test_odepack.py b/tests/solvers/test_odepack.py
index 212a9b97..297bbb91 100644
--- a/tests/solvers/test_odepack.py
+++ b/tests/solvers/test_odepack.py
@@ -123,6 +123,7 @@ class Test_LSODAR:
     Tests the LSODAR solver.
     """
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This sets up the test case.
@@ -192,9 +193,9 @@ def test_event_localizer(self):
         t, y = exp_sim.simulate(10.0,1000) #Simulate 10 seconds with 1000 communications points
         
         #Basic test
-        assert_almost_equal(y[-1][0],8.0)
-        assert_almost_equal(y[-1][1],3.0)
-        assert_almost_equal(y[-1][2],2.0)
+        assert y[-1][0] == pytest.approx(8.0)
+        assert y[-1][1] == pytest.approx(3.0)
+        assert y[-1][2] == pytest.approx(2.0)
 
     @testattr(stddist = True)
     def test_simulation(self):
@@ -203,13 +204,13 @@ def test_simulation(self):
         """
         self.sim.simulate(1.) #Simulate 2 seconds
 
-        assert self.sim.y_sol[-1][0] == pytest.approx(-1.863646028, rel = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(-1.863646028, abs = 1e-4)
     
     @testattr(stddist = True)
     def test_setcoefficients(self):
         elco,tesco=dcfode(1)
-        assert_almost_equal(elco[0,2],5./12.,9) # AM-2
-        assert_almost_equal(tesco[0,2],2.,9) # AM-2 error coeff  
+        assert elco[0,2] == pytest.approx(5./12., abs = 1e-9) # AM-2
+        assert tesco[0,2] == pytest.approx(2., abs = 1e-9) # AM-2 error coeff  
     
     @testattr(stddist = True)
     def test_readcommon(self):
@@ -220,7 +221,7 @@ def test_readcommon(self):
         r=np.ones((245,),'d')
         i=np.ones((55,),'i')
         dsrcar(r,i,1)
-        assert r[217] == pytest.approx(2.22044605e-16, rel = 1e-20)
+        assert r[217] == pytest.approx(2.22044605e-16, abs = 1e-20)
         assert i[36] == 3
         
     @testattr(stddist = True)
@@ -234,7 +235,7 @@ def test_writereadcommon(self):
         r[0]=100.
         i[0]=10
         dsrcar(r,i,1)
-        assert r[0] == pytest.approx(1., rel = 1e-4)
+        assert r[0] == pytest.approx(1., abs = 1e-4)
         assert i[0] == 1  
     
     def test_rkstarter(self):
@@ -276,7 +277,7 @@ def test_interpol(self):
         self.sim.reset()
         t_sol1,y_sol1=self.sim.simulate(0.5)
         ind05=np.nonzero(np.array(t_sol)==0.5)[0][0]
-        assert_almost_equal(y_sol[ind05,0],y_sol1[-1,0],6)
+        assert y_sol[ind05,0] == pytest.approx(y_sol1[-1,0], abs = 1e-6)
         
     @testattr(stddist = True)
     def test_simulation_with_jac(self):
@@ -286,13 +287,13 @@ def test_simulation_with_jac(self):
         self.sim.usejac = True
         self.sim.simulate(1.) #Simulate 2 seconds
 
-        assert self.sim.y_sol[-1][0] == pytest.approx(-1.863646028, rel = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(-1.863646028, abs = 1e-4)
     
     @testattr(stddist = True)    
     def test_simulation_ncp(self):
         self.sim.simulate(1.,100) #Simulate 2 seconds
 
-        assert self.sim.y_sol[-1][0] == pytest.approx(-1.863646028, rel = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(-1.863646028, abs = 1e-4)
         
     @testattr(stddist = True)
     def test_usejac_csc_matrix(self):
@@ -302,13 +303,13 @@ def test_usejac_csc_matrix(self):
     
         assert self.sim_sp.statistics["nfcnjacs"] == 0
         
-        assert self.sim_sp.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        assert self.sim_sp.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
         
     @testattr(stddist = True)    
     def test_simulation_ncp_list(self):
         self.sim.simulate(1.,ncp_list=[0.5]) #Simulate 2 seconds
 
-        assert self.sim.y_sol[-1][0] == pytest.approx(-1.863646028, rel = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(-1.863646028, abs = 1e-4)
         
     @testattr(stddist = True)    
     def test_maxh(self):
@@ -325,7 +326,7 @@ def test_maxh(self):
     def test_simulation_ncp_list_2(self):
         self.sim.simulate(1.,ncp_list=[0.5,4]) #Simulate 2 seconds
 
-        assert self.sim.y_sol[-1][0] == pytest.approx(-1.863646028, rel = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(-1.863646028, abs = 1e-4)
         
     @testattr(stddist = True)    
     def test_simulation_ncp_with_jac(self):
@@ -335,7 +336,7 @@ def test_simulation_ncp_with_jac(self):
         self.sim.usejac= True
         self.sim.simulate(1.,100) #Simulate 2 seconds
 
-        assert self.sim.y_sol[-1][0] == pytest.approx(-1.863646028, rel = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(-1.863646028, abs = 1e-4)
 
     @testattr(stddist = True)
     def test_time_limit(self):
diff --git a/tests/solvers/test_radau5.py b/tests/solvers/test_radau5.py
index 24a11710..641398f3 100644
--- a/tests/solvers/test_radau5.py
+++ b/tests/solvers/test_radau5.py
@@ -170,6 +170,7 @@ class Test_Explicit_Radau5_Py:
     Tests the explicit Radau solver (Python implementation).
     """
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This sets up the test case.
@@ -227,9 +228,9 @@ def test_event_localizer(self):
     #     t, y = exp_sim.simulate(10.0,1000) #Simulate 10 seconds with 1000 communications points
         
     #     #Basic test
-    #     assert_almost_equal(y[-1][0],8.0)
-    #     assert_almost_equal(y[-1][1],3.0)
-    #     assert_almost_equal(y[-1][2],2.0)
+    #     assert y[-1][0] == pytest.approx(8.0)
+    #     assert y[-1][1] == pytest.approx(3.0)
+    #     assert y[-1][2] == pytest.approx(2.0)
     
     @testattr(stddist = True)
     def test_time_event(self):
@@ -286,9 +287,9 @@ def test_collocation_polynomial(self):
         
         assert self.sim.statistics["nsteps"] < 300
         
-        #assert self.sim.y[-2][0] == pytest.approx(1.71505001, rel = 1e-4)
+        #assert self.sim.y[-2][0] == pytest.approx(1.71505001, abs = 1e-4)
         print
-        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
         
         self.sim.report_continuously = True
         self.sim.reset()
@@ -296,13 +297,13 @@ def test_collocation_polynomial(self):
         
         assert self.sim.statistics["nsteps"] < 300
 
-        #assert self.sim.y[-2][0] == pytest.approx(1.71505001, rel = 1e-4)
-        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        #assert self.sim.y[-2][0] == pytest.approx(1.71505001, abs = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
         
         self.sim_t0.simulate(3.)
-        assert self.sim_t0.t_sol[0] == pytest.approx(1.0000000, rel = 1e-4)
-        assert self.sim_t0.t_sol[-1] == pytest.approx(3.0000000, rel = 1e-4)
-        assert self.sim_t0.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        assert self.sim_t0.t_sol[0] == pytest.approx(1.0000000, abs = 1e-4)
+        assert self.sim_t0.t_sol[-1] == pytest.approx(3.0000000, abs = 1e-4)
+        assert self.sim_t0.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
         
     @testattr(stddist = True)
     def test_simulation(self):
@@ -313,7 +314,7 @@ def test_simulation(self):
         
         assert self.sim.statistics["nsteps"] < 300
 
-        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
     
     @testattr(stddist = True)    
     def test_simulation_ncp(self):
@@ -342,7 +343,7 @@ def test_usejac(self):
 
         assert self.sim.statistics["nfcnjacs"] == 0
         
-        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
 
     @testattr(stddist = True)
     def test_thet(self):
@@ -422,7 +423,7 @@ def test_atol(self):
         assert steps3 == steps2
 
         err_msg = "atol must be of length one or same as the dimension of the problem."
-        with pytest.raises(Radau_Exception, err_msg):
+        with pytest.raises(Radau_Exception, match = err_msg):
             self.sim.atol = [1e-6,1e-6,1e-6]
         
 class Test_Explicit_Radau5:
@@ -430,6 +431,7 @@ class Test_Explicit_Radau5:
     Tests the explicit Radau solver.
     """
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This sets up the test case.
@@ -501,9 +503,9 @@ def test_event_localizer(self):
         t, y = exp_sim.simulate(10.0,1000) #Simulate 10 seconds with 1000 communications points
         
         #Basic test
-        assert_almost_equal(y[-1][0],8.0)
-        assert_almost_equal(y[-1][1],3.0)
-        assert_almost_equal(y[-1][2],2.0)
+        assert y[-1][0] == pytest.approx(8.0)
+        assert y[-1][1] == pytest.approx(3.0)
+        assert y[-1][2] == pytest.approx(2.0)
     
     @testattr(stddist = True)
     def test_nbr_fcn_evals_due_to_jac(self):
@@ -574,8 +576,8 @@ def test_collocation_polynomial(self):
         
         assert self.sim.statistics["nsteps"] < 300
         
-        #assert self.sim.y[-2][0] == pytest.approx(1.71505001, rel = 1e-4)
-        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        #assert self.sim.y[-2][0] == pytest.approx(1.71505001, abs = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
         
         self.sim.report_continuously = True
         self.sim.reset()
@@ -583,13 +585,13 @@ def test_collocation_polynomial(self):
         
         assert self.sim.statistics["nsteps"] < 300
 
-        #assert self.sim.y[-2][0] == pytest.approx(1.71505001, rel = 1e-4)
-        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        #assert self.sim.y[-2][0] == pytest.approx(1.71505001, abs = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
         
         self.sim_t0.simulate(3.)
-        assert self.sim_t0.t_sol[0] == pytest.approx(1.0000000, rel = 1e-4)
-        assert self.sim_t0.t_sol[-1] == pytest.approx(3.0000000, rel = 1e-4)
-        assert self.sim_t0.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        assert self.sim_t0.t_sol[0] == pytest.approx(1.0000000, abs = 1e-4)
+        assert self.sim_t0.t_sol[-1] == pytest.approx(3.0000000, abs = 1e-4)
+        assert self.sim_t0.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
         
     @testattr(stddist = True)
     def test_simulation(self):
@@ -600,7 +602,7 @@ def test_simulation(self):
         
         assert self.sim.statistics["nsteps"] < 300
 
-        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
     
     @testattr(stddist = True)    
     def test_simulation_ncp(self):
@@ -629,7 +631,7 @@ def test_usejac(self):
 
         assert self.sim.statistics["nfcnjacs"] == 0
         
-        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        assert self.sim.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
     
     @testattr(stddist = True)
     def test_usejac_csc_matrix(self):
@@ -642,7 +644,7 @@ def test_usejac_csc_matrix(self):
     
         assert self.sim_sp.statistics["nfcnjacs"] == 0
         
-        assert self.sim_sp.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        assert self.sim_sp.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
     
     @testattr(stddist = True)
     def test_thet(self):
@@ -673,7 +675,7 @@ def test_newt(self):
         # self.sim.reset()
         # self.sim.newt = 10
         # self.sim.simulate(1.0)
-        # assert_equal(self.sim.statistics["nniterfail"], 1)
+        # assert self.sim.statistics["nniterfail"] == 1
     
     @testattr(stddist = True)
     def test_safe(self):
@@ -738,7 +740,7 @@ def test_atol(self):
         assert steps3 == steps2
         
         err_msg = "atol must be of length one or same as the dimension of the problem."
-        with pytest.raises(Radau_Exception, err_msg):
+        with pytest.raises(Radau_Exception, match = err_msg):
             self.sim.atol = [1e-6,1e-6,1e-6]
         
     @testattr(stddist = True)
@@ -773,7 +775,7 @@ def test_nmax_steps(self):
         sim.maxsteps = 9
 
         err_msg = f'Radau5 failed with flag -5. At time {float_regex}. Message: Maximal number of steps = 9 exceeded.'
-        with pytest.raises(Radau5Error, err_msg):
+        with pytest.raises(Radau5Error, match = err_msg):
             sim.simulate(1.)
 
     @testattr(stddist = True)
@@ -790,7 +792,7 @@ def test_step_size_too_small(self):
         sim.maxh = 1.e-1
 
         err_msg = f"Radau5 failed with flag -6. At time {float_regex}. Message: Stepsize too small with h = {float_regex}."
-        with pytest.raises(Radau5Error, err_msg):
+        with pytest.raises(Radau5Error, match = err_msg):
             sim.simulate(1. + 1.e-16)
 
     @testattr(stddist = True)
@@ -805,7 +807,7 @@ def f(t, y):
         sim = Radau5ODE(prob)
 
         err_msg = f'Repeated unexpected step rejections.'
-        with pytest.raises(Radau5Error, err_msg):
+        with pytest.raises(Radau5Error, match = err_msg):
             sim.simulate(1.)
 
     @testattr(stddist = True)
@@ -837,7 +839,7 @@ def test_solver_no_jac(self):
         sim.usejac = True
 
         err_msg = "Use of an analytical Jacobian is enabled, but problem does contain a 'jac' function."
-        with pytest.raises(Radau_Exception, err_msg):
+        with pytest.raises(Radau_Exception, match = err_msg):
             sim.simulate(1.)
 
     @testattr(stddist = True)
@@ -857,7 +859,7 @@ def test_solver_sparse_jac_wrong_format(self):
         sim.usejac = True
 
         err_msg = f'Radau5 failed with flag -11. At time {float_regex}. Message: Jacobian given in wrong format, required sparsity format: CSC.'
-        with pytest.raises(Radau5Error, err_msg):
+        with pytest.raises(Radau5Error, match = err_msg):
             sim.simulate(1.)
 
     @testattr(stddist = True)
@@ -878,7 +880,7 @@ def test_solver_sparse_jac_nnz_too_small(self):
         sim.usejac = True
 
         err_msg = f'Radau5 failed with flag -9. At time {float_regex}. Message: Number of nonzero elements in provided jacobian is too small, specified = 1, actual = 5.'
-        with pytest.raises(Radau5Error, err_msg):
+        with pytest.raises(Radau5Error, match = err_msg):
             sim.simulate(1.)
 
     @testattr(stddist = True)
@@ -916,7 +918,7 @@ def test_sparse_solver_no_nnz(self):
         sim.usejac = True
 
         err_msg = "Number of non-zero elements of sparse Jacobian must be non-negative. Detected default value of '-1', has 'problem.jac_fcn_nnz' been set?"
-        with pytest.raises(Radau_Exception, err_msg):
+        with pytest.raises(Radau_Exception, match = err_msg):
             sim.simulate(1.)
 
     @testattr(stddist = True)
@@ -938,7 +940,7 @@ def test_sparse_solver_invalid_nnz_type(self):
             sim.usejac = True
 
             err_msg = "Number of non-zero elements of sparse Jacobian must be an integer, received: {}."
-            with pytest.raises(Radau_Exception, err_msg.format(nnz)):
+            with pytest.raises(Radau_Exception, match = err_msg.format(nnz)):
                 sim.simulate(1.)
 
     @testattr(stddist = True)
@@ -960,7 +962,7 @@ def test_sparse_solver_invalid_nnz_negative(self):
             sim.usejac = True
 
             err_msg = "Number of non-zero elements of sparse Jacobian must be non-negative, given value = {}."
-            with pytest.raises(Radau_Exception, err_msg.format(nnz)):
+            with pytest.raises(Radau_Exception, match = err_msg.format(nnz)):
                 sim.simulate(1.)
 
     @testattr(stddist = True)
@@ -982,7 +984,7 @@ def test_sparse_solver_invalid_nnz_too_large(self):
             sim.usejac = True
 
             err_msg = "Number of non-zero elements of sparse Jacobian infeasible, must be smaller than the problem dimension squared."
-            with pytest.raises(Radau_Exception, err_msg):
+            with pytest.raises(Radau_Exception, match = err_msg):
                 sim.simulate(1.)
 
     def test_sparse_solver_jacobian(self):
@@ -1011,7 +1013,7 @@ def test_sparse_solver_jacobian(self):
             sim.linear_solver = 'SPARSE'
             sim.usejac = True
 
-            ok_(sim.simulate(1.), msg = f"Jacobian #{i} failed: {jac(0, 0)}")
+            assert sim.simulate(1.), f"Jacobian #{i} failed: {jac(0, 0)}"
 
     @testattr(stddist = True)
     def test_linear_solver(self):
@@ -1028,13 +1030,13 @@ def test_linear_solver(self):
         assert self.sim.linear_solver == 'SPARSE'
 
         err_msg = "'linear_solver' parameter needs to be either 'DENSE' or 'SPARSE'. Set value: {}"
-        with pytest.raises(Radau_Exception, err_msg.format('default')):
+        with pytest.raises(Radau_Exception, match = err_msg.format('default')):
             self.sim.linear_solver = 'default'
-        with pytest.raises(Radau_Exception, err_msg.format('GMRES')):
+        with pytest.raises(Radau_Exception, match = err_msg.format('GMRES')):
             self.sim.linear_solver = 'GMRES'
 
         err_msg = "'linear_solver' parameter needs to be the STRING 'DENSE' or 'SPARSE'. Set value: {}, type: {}"
-        with pytest.raises(Radau_Exception, err_msg.format('0', "<class 'int'>")):
+        with pytest.raises(Radau_Exception, match = err_msg.format('0', "<class 'int'>")):
             self.sim.linear_solver = 0
 
     @testattr(stddist = True)
@@ -1157,6 +1159,7 @@ class Test_Implicit_Radau5:
     Tests the implicit Radau solver.
     """
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This sets up the test case.
@@ -1202,7 +1205,7 @@ def test_implementation_set(self):
             Test setting of implementation property of Radau5DAE.
         """
         err_msg = "Radau5DAE does not support setting the 'implementation' attribute, since it only supports the Fortran implementation of Radau5."
-        with pytest.raises(Radau_Exception, err_msg):
+        with pytest.raises(Radau_Exception, match = err_msg):
             self.sim.implementation = 'c'
 
     @testattr(stddist = True)
@@ -1218,7 +1221,7 @@ def test_linear_solver_set(self):
             Test setting of linear_solver property of Radau5DAE.
         """
         err_msg = "Radau5DAE does not support setting the 'linear_solver' attribute, since it only supports the DENSE linear solver in Fortran implementation of Radau5."
-        with pytest.raises(Radau_Exception, err_msg):
+        with pytest.raises(Radau_Exception, match = err_msg):
             self.sim.linear_solver = 'SPARSE'
     
     @testattr(stddist = True)
@@ -1311,7 +1314,7 @@ def test_simulation(self):
         """
         #Simulate
         self.sim.simulate(2.) #Simulate 2 seconds
-        assert self.sim.y_sol[-1][0] == pytest.approx(1.706272, rel = 1e-3)
+        assert self.sim.y_sol[-1][0] == pytest.approx(1.706272, abs = 1e-3)
 
         self.sim.reset()
 
@@ -1319,12 +1322,12 @@ def test_simulation(self):
 
         #Simulate
         self.sim.simulate(2.) #Simulate 2 seconds
-        assert self.sim.y_sol[-1][0] == pytest.approx(1.706166, rel = 1e-3)
+        assert self.sim.y_sol[-1][0] == pytest.approx(1.706166, abs = 1e-3)
 
         self.sim_t0.simulate(3.)
-        assert self.sim_t0.t_sol[0] == pytest.approx(1.0000000, rel = 1e-4)
-        assert self.sim_t0.t_sol[-1] == pytest.approx(3.0000000, rel = 1e-4)
-        assert self.sim_t0.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        assert self.sim_t0.t_sol[0] == pytest.approx(1.0000000, abs = 1e-4)
+        assert self.sim_t0.t_sol[-1] == pytest.approx(3.0000000, abs = 1e-4)
+        assert self.sim_t0.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
 
     @testattr(stddist = True)    
     def test_simulation_ncp(self):
@@ -1384,7 +1387,7 @@ def test_nmax_steps(self):
         sim.maxsteps = 9
 
         err_msg = "The solver took max internal steps but could not reach the next output time."
-        with pytest.raises(Radau5Error, err_msg):
+        with pytest.raises(Radau5Error, match = err_msg):
             sim.simulate(1.)
 
     @testattr(stddist = True)
@@ -1407,7 +1410,7 @@ def test_step_size_too_small(self):
         sim.maxh = 1.e-1
         
         err_msg = f"The step size became too small. At time {float_regex}."
-        with pytest.raises(Radau5Error, err_msg):
+        with pytest.raises(Radau5Error, match = err_msg):
             sim.simulate(1. + 1.e-16)
 
     @testattr(stddist = True)
@@ -1420,8 +1423,8 @@ def f(t, y, yd):
         prob = Implicit_Problem(f, np.array([1.]), np.array([1.]))
         sim = Radau5DAE(prob)
 
-        err_msg = f'Repeated unexpected step rejections.'
-        with pytest.raises(Radau5Error, err_msg):
+        err_msg = 'Repeated unexpected step rejections.'
+        with pytest.raises(Radau5Error, match = err_msg):
             sim.simulate(1.)
 
 
@@ -1430,6 +1433,7 @@ class Test_Implicit_Radau5_Py:
     Tests the implicit Radau solver (Python implementation).
     """
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This sets up the test case.
@@ -1527,7 +1531,7 @@ def test_simulation(self):
         """
         #Simulate
         self.sim.simulate(2.) #Simulate 2 seconds
-        assert self.sim.y_sol[-1][0] == pytest.approx(1.706272, rel = 1e-3)
+        assert self.sim.y_sol[-1][0] == pytest.approx(1.706272, abs = 1e-3)
         
         self.sim.reset()
         
@@ -1535,12 +1539,12 @@ def test_simulation(self):
         
         #Simulate
         self.sim.simulate(2.) #Simulate 2 seconds
-        assert self.sim.y_sol[-1][0] == pytest.approx(1.706947, rel = 1e-2)
+        assert self.sim.y_sol[-1][0] == pytest.approx(1.706947, abs = 1e-2)
         
         self.sim_t0.simulate(3.)
-        assert self.sim_t0.t_sol[0] == pytest.approx(1.0000000, rel = 1e-4)
-        assert self.sim_t0.t_sol[-1] == pytest.approx(3.0000000, rel = 1e-4)
-        assert self.sim_t0.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        assert self.sim_t0.t_sol[0] == pytest.approx(1.0000000, abs = 1e-4)
+        assert self.sim_t0.t_sol[-1] == pytest.approx(3.0000000, abs = 1e-4)
+        assert self.sim_t0.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
     
     @testattr(stddist = True)    
     def test_simulation_ncp(self):
@@ -1578,7 +1582,7 @@ def test_keyboard_interrupt_fcn(self):
         sim = Radau5DAE(prob)
 
         err_msg = "Unrecoverable exception encountered during callback to problem (right-hand side/jacobian)."
-        with pytest.raises(Radau5Error, re.escape(err_msg)):
+        with pytest.raises(Radau5Error, match = re.escape(err_msg)):
             sim.simulate(1.)
 
 class Test_Radau_Common:
@@ -1586,6 +1590,7 @@ class Test_Radau_Common:
     Tests the common attributes of the Radau solvers.
     """
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This sets up the test case.
diff --git a/tests/solvers/test_rosenbrock.py b/tests/solvers/test_rosenbrock.py
index 79f9b270..19ef8399 100644
--- a/tests/solvers/test_rosenbrock.py
+++ b/tests/solvers/test_rosenbrock.py
@@ -27,6 +27,7 @@
 
 class Test_RodasODE:
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         #Define the rhs
         def f(t,y):
@@ -90,7 +91,7 @@ def test_usejac_csc_matrix(self):
     
         assert sim.statistics["nfcnjacs"] == 0
         
-        assert sim.y_sol[-1][0] == pytest.approx(1.7061680350, rel = 1e-4)
+        assert sim.y_sol[-1][0] == pytest.approx(1.7061680350, abs = 1e-4)
 
     @testattr(stddist = True)
     def test_time_limit(self):
diff --git a/tests/solvers/test_rungekutta.py b/tests/solvers/test_rungekutta.py
index a36aaec3..33927b00 100644
--- a/tests/solvers/test_rungekutta.py
+++ b/tests/solvers/test_rungekutta.py
@@ -27,6 +27,7 @@
 class Test_Dopri5:
     
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This function sets up the test case.
@@ -125,6 +126,7 @@ def f(t, y):
 class Test_RungeKutta34:
     
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This function sets up the test case.
@@ -261,6 +263,7 @@ def f(t, y):
 class Test_RungeKutta4:
     
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This function sets up the test case.
diff --git a/tests/solvers/test_sundials.py b/tests/solvers/test_sundials.py
index 853d2e58..78c65f49 100644
--- a/tests/solvers/test_sundials.py
+++ b/tests/solvers/test_sundials.py
@@ -117,6 +117,7 @@ def init_mode(self, solver):
 class Test_CVode:
     
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This function sets up the test case.
@@ -201,7 +202,7 @@ def test_get_used_initial_step(self):
         self.simulator.simulate(1.0)
         
         step = self.simulator.get_used_initial_step()
-        assert step == pytest.approx(0.001, rel = 1e-3)
+        assert step == pytest.approx(0.001, abs = 1e-3)
         
         self.simulator.reset()
         
@@ -279,7 +280,7 @@ def test_init(self):
         """
         This tests the functionality of the method __init__.
         """
-        # assert_equal(self.simulator.f, 'Test function')
+        # assert self.simulator.f == 'Test function'
         assert self.simulator.y == 1.0
         assert self.simulator.discr == 'BDF'
         assert self.simulator.iter == 'Newton'
@@ -496,13 +497,13 @@ def test_usejac(self):
         exp_sim.simulate(5.,100)
         
         assert exp_sim.statistics["nfcnjacs"] == 0
-        assert exp_sim.y_sol[-1][0] == pytest.approx(-121.75000143, rel = 1e-4)
+        assert exp_sim.y_sol[-1][0] == pytest.approx(-121.75000143, abs = 1e-4)
         
         exp_sim.reset()
         exp_sim.usejac=False
         exp_sim.simulate(5.,100)
 
-        assert exp_sim.y_sol[-1][0] == pytest.approx(-121.75000143, rel = 1e-4)
+        assert exp_sim.y_sol[-1][0] == pytest.approx(-121.75000143, abs = 1e-4)
         assert exp_sim.statistics["nfcnjacs"] > 0
     
     @testattr(stddist = True)
@@ -522,13 +523,13 @@ def test_usejac_csc_matrix(self):
         exp_sim.simulate(5.,100)
         
         assert exp_sim.statistics["nfcnjacs"] == 0
-        assert exp_sim.y_sol[-1][0] == pytest.approx(-121.75000143, rel = 1e-4)
+        assert exp_sim.y_sol[-1][0] == pytest.approx(-121.75000143, abs = 1e-4)
         
         exp_sim.reset()
         exp_sim.usejac=False
         exp_sim.simulate(5.,100)
 
-        assert exp_sim.y_sol[-1][0] == pytest.approx(-121.75000143, rel = 1e-4)
+        assert exp_sim.y_sol[-1][0] == pytest.approx(-121.75000143, abs = 1e-4)
         assert exp_sim.statistics["nfcnjacs"] > 0
     
     @testattr(stddist = True)
@@ -608,7 +609,7 @@ def test_interpolate(self):
         t100 = sim.t_sol
         sim.reset()
         sim.simulate(10.)
-        assert_almost_equal(float(y100[-2]), float(sim.interpolate(9.9,0)),5)
+        assert float(y100[-2]) == pytest.approx(float(sim.interpolate(9.9, 0)), abs = 1e-5)
     
     @testattr(stddist = True)
     def test_ncp_list(self):
@@ -620,7 +621,7 @@ def test_ncp_list(self):
         
         t, y = sim.simulate(7, ncp_list=np.arange(0, 7, 0.1)) #Simulate 5 seconds
         
-        assert float(y[-1]) == pytest.approx(0.00364832, rel = 1e-4)
+        assert float(y[-1]) == pytest.approx(0.00364832, abs = 1e-4)
         
     @testattr(stddist = True)
     def test_handle_result(self):
@@ -691,8 +692,8 @@ def run_sim(exp_mod):
             t, y = exp_sim.simulate(5, 1000) #Simulate 5 seconds with 1000 communication points
         
             #Basic tests
-            assert_almost_equal(y[-1][0],-121.75000000,4)
-            assert_almost_equal(y[-1][1],-49.100000000)
+            assert y[-1][0] == pytest.approx(-121.75000000, abs = 1e-4)
+            assert y[-1][1] == pytest.approx(-49.100000000)
         
         exp_mod = Explicit_Problem(f,y0)
         exp_mod.jacv = jacv #Sets the jacobian
@@ -821,7 +822,7 @@ def handle_event(self, solver, event_info):
         simulator = CVode(exp_mod)
         simulator(3.)
         
-        assert simulator.t == pytest.approx(2.000000, rel = 1e-4)
+        assert simulator.t == pytest.approx(2.000000, abs = 1e-4)
     
     @testattr(stddist = True)
     def test_completed_step(self):
@@ -919,6 +920,7 @@ def test_rtol_vector_sense(self):
 class Test_IDA:
     
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This function sets up the test case.
@@ -968,7 +970,7 @@ def test_init(self):
         """
         assert not self.simulator.suppress_alg
         assert self.simulator.algvar[0] == 1.0
-        assert self.simulator.sw == None
+        assert self.simulator.sw is None
         assert self.simulator.maxsteps == 10000
         assert self.simulator.y[0] == 1.0
     
@@ -987,7 +989,7 @@ def test_interpolate(self):
         t100 = sim.t_sol
         sim.reset()
         sim.simulate(10.)
-        assert_almost_equal(y100[-2], sim.interpolate(9.9,0),5)
+        assert y100[-2] == pytest.approx(sim.interpolate(9.9, 0), abs = 1e-5)
     
     @testattr(stddist = True)
     def test_handle_result(self):
@@ -1071,13 +1073,13 @@ def f(t,y,yd):
         sim = IDA(mod)
         sim.simulate(2.0)
 
-        assert sim.y_sol[-1][0] == pytest.approx(-13.4746473811, rel = 1e-7)
+        assert sim.y_sol[-1][0] == pytest.approx(-13.4746473811, abs = 1e-7)
         
         sim.reset()
         sim.inith = 1e-10
         sim.simulate(2.0)
 
-        assert sim.y_sol[-1][0] == pytest.approx(-13.4746596311, rel = 1e-7)
+        assert sim.y_sol[-1][0] == pytest.approx(-13.4746596311, abs = 1e-7)
         
     @testattr(stddist = True)
     def test_time_event(self):
@@ -1114,9 +1116,9 @@ def handle_event(solver, event_info):
         
         sim.simulate(5.0)
 
-        assert sim.y_sol[38] == pytest.approx(1.0000000, rel = 1e-5)
-        assert sim.y_sol[87] == pytest.approx(1.0000000, rel = 1e-5)
-        assert sim.t_sol[-1] == pytest.approx(5.0000000, rel = 1e-5)
+        assert sim.y_sol[38] == pytest.approx(1.0000000, abs = 1e-5)
+        assert sim.y_sol[87] == pytest.approx(1.0000000, abs = 1e-5)
+        assert sim.t_sol[-1] == pytest.approx(5.0000000, abs = 1e-5)
     
     @testattr(stddist = True)
     def test_clear_event_log(self):
@@ -1175,13 +1177,13 @@ def test_usejac(self):
         imp_sim.simulate(3,100)
 
         assert imp_sim.statistics["nfcnjacs"] == 0
-        assert imp_sim.y_sol[-1][0] == pytest.approx(45.1900000, rel = 1e-4)
+        assert imp_sim.y_sol[-1][0] == pytest.approx(45.1900000, abs = 1e-4)
         
         imp_sim.reset()
         imp_sim.usejac=False
         imp_sim.simulate(3.,100)
 
-        assert imp_sim.y_sol[-1][0] == pytest.approx(45.1900000, rel = 1e-4)
+        assert imp_sim.y_sol[-1][0] == pytest.approx(45.1900000, abs = 1e-4)
         assert imp_sim.statistics["nfcnjacs"] > 0
     
     @testattr(stddist = True)
@@ -1204,7 +1206,7 @@ def handle_event(self,solver, event_info):
         sim = IDA(prob)
         sim.simulate(2.5)
         
-        assert sim.t == pytest.approx(2.000000, rel = 1e-4)
+        assert sim.t == pytest.approx(2.000000, abs = 1e-4)
 
     @testattr(stddist = True)
     def test_terminate_simulation_external_event(self):
@@ -1227,7 +1229,7 @@ def handle_event(self,solver, event_info):
         sim.external_event_detection = True
         sim.simulate(2.5)
         
-        assert sim.t == pytest.approx(2.000000, rel = 1e-4)
+        assert sim.t == pytest.approx(2.000000, abs = 1e-4)
     
     @testattr(stddist = True)    
     def test_algvar(self):
@@ -1258,9 +1260,9 @@ def test_algvar(self):
         #self.simulator.algvar = vectorb
         #self.simulator.algvar = vectori
         #self.simulator.algvar = vector
-        #assert_equal(self.simulator.algvar[0], vector[0])
-        #assert_equal(self.simulator.algvar[1], vector[1])
-        #assert_equal(self.simulator.algvar[2], vector[2])
+        #assert self.simulator.algvar[0] == vector[0]
+        #assert self.simulator.algvar[1] == vector[1]
+        #assert self.simulator.algvar[2] == vector[2]
     
     @testattr(stddist = True)
     def test_time_event_2(self):
@@ -1390,6 +1392,7 @@ def completed_step(solver):
 class Test_Sundials:
     
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         """
         This sets up the test case.
@@ -1456,11 +1459,11 @@ def test_atol(self):
             with pytest.raises(Exception):
             self.simulators([i]._set_atol, [1.0, 1.0, -1.0])
             self.simulators[i].atol = [1.0, 1.0, 1.0]
-            assert_equal(self.simulators[i].atol, [1.0, 1.0, 1.0])
+            assert self.simulators[i].atol == [1.0, 1.0, 1.0]
             self.simulators[i].atol = np.array([1.0, 1.0, 1.0])
-            assert_equal(self.simulators[i].atol[0], 1.0)
+            assert self.simulators[i].atol[0] == 1.0
             self.simulators[i].atol = np.array([1, 5, 1.0])
-            assert_equal(self.simulators[i].atol[0], 1.0)
+            assert self.simulators[i].atol[0] == 1.0
             """
     
     
@@ -1636,8 +1639,8 @@ def test_pbar(self):
         
         exp_sim = CVode(exp_mod)
 
-        assert exp_sim.pbar[0] == pytest.approx(1000.00000, rel = 1e-4)
-        assert exp_sim.pbar[1] == pytest.approx(100.000000, rel = 1e-4)
+        assert exp_sim.pbar[0] == pytest.approx(1000.00000, abs = 1e-4)
+        assert exp_sim.pbar[1] == pytest.approx(100.000000, abs = 1e-4)
         
         f = lambda t,y,yd,p: np.array([0.0]*len(y))
         yd0 = [0.0]*2
@@ -1645,5 +1648,5 @@ def test_pbar(self):
         
         imp_sim = IDA(imp_mod)
         
-        assert imp_sim.pbar[0] == pytest.approx(1000.00000, rel = 1e-4)
-        assert imp_sim.pbar[1] == pytest.approx(100.000000, rel = 1e-4)
+        assert imp_sim.pbar[0] == pytest.approx(1000.00000, abs = 1e-4)
+        assert imp_sim.pbar[1] == pytest.approx(100.000000, abs = 1e-4)
diff --git a/tests/test_ode.py b/tests/test_ode.py
index f67a808a..83429e69 100644
--- a/tests/test_ode.py
+++ b/tests/test_ode.py
@@ -23,6 +23,7 @@
 
 class Test_ODE:
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         cls.problem = Explicit_Problem(y0=4.0)
         cls.simulator = ODE(cls.problem)
diff --git a/tests/test_solvers.py b/tests/test_solvers.py
index 88777fca..05691799 100644
--- a/tests/test_solvers.py
+++ b/tests/test_solvers.py
@@ -34,6 +34,7 @@ def handle_event(solver, event_info):
 
 class Test_Solvers:
     @classmethod
+    @pytest.fixture(autouse=True)
     def setup_class(cls):
         cls.problem = Implicit_Problem(res, [1.0], [-1.0])
         cls.problem.state_events = state_events
@@ -49,7 +50,7 @@ def test_radau5dae_state_events(self):
         
         t,y,yd = solver.simulate(2,33)
         
-        assert float(y[-1]) == pytest.approx(0.135, rel = 1e-3)
+        assert float(y[-1]) == pytest.approx(0.135, abs = 1e-3)
         
     @testattr(stddist = True)
     def test_dopri5_state_events(self):
@@ -57,7 +58,7 @@ def test_dopri5_state_events(self):
         
         t,y = solver.simulate(2,33)
         
-        assert float(y[-1]) == pytest.approx(0.135, rel = 1e-3)
+        assert float(y[-1]) == pytest.approx(0.135, abs = 1e-3)
         
     @testattr(stddist = True)
     def test_rodasode_state_events(self):
@@ -65,4 +66,4 @@ def test_rodasode_state_events(self):
         
         t,y = solver.simulate(2,33)
         
-        assert float(y[-1]) == pytest.approx(0.135, rel = 1e-3)
+        assert float(y[-1]) == pytest.approx(0.135, abs = 1e-3)