diff --git a/test/data_for_test.py b/test/data_for_test.py
index 255932e00adfc106c748306046ce40c3f133b92a..483d50b65f311b8cabea7497b1b1626590b62032 100644
--- a/test/data_for_test.py
+++ b/test/data_for_test.py
@@ -48,8 +48,16 @@ class WindowData:
 @pytest.fixture(scope="session")
 def states_generator():
     def states(states_str):
-        state_pair = u.transposed_array_from_string(states_str)
-        return u.expand_to_n(state_pair, 6)
+        if states_str == "sine":
+            rho = np.sin(0.01*np.arange(6)+1.55)
+            vel = np.repeat(np.array([1.0, 2.0, 3.0])[None,:], 6, axis=0)
+            pressure = np.repeat(3.2, 6)
+            return u.transposed_array([ref.gas.conserved(r, v, p)
+                for r, v, p
+                in zip(rho, vel, pressure)])
+        else:
+            state_pair = u.transposed_array_from_string(states_str)
+            return u.expand_to_n(state_pair, 6)
 
     return states
 
@@ -72,6 +80,9 @@ def metrics_generator():
 
 
 @pytest.fixture(scope="session", params=[
+    ("sine", "x", "uniform"),
+    ("sine", "y", "uniform"),
+    ("sine", "z", "uniform"),
     ("1 1 1 1 5.5,1 1 1 1 5.5", "x", "uniform"),
     ("1 1 1 1 5.5,1 1 1 1 5.5", "y", "uniform"),
     ("1 1 1 1 5.5,1 1 1 1 5.5", "z", "uniform"),
diff --git a/test/ideal_gas.py b/test/ideal_gas.py
index 0be569fef27f36ab0a3dbc5ec0b15033a84eea09..85aa4b737a985ef7c0b83d1cec7fa9c9ca59d41a 100644
--- a/test/ideal_gas.py
+++ b/test/ideal_gas.py
@@ -47,13 +47,12 @@ def energy(state):
     return state[ndim+1]
 
 
-def kinetic_energy(state):
-    vel = velocity(state)
-    return 0.5*rho(state)*np.dot(vel, vel)
+def kinetic_energy(rho, vel):
+    return 0.5*rho*np.dot(vel, vel)
 
 
 def internal_energy(state):
-    return energy(state) - kinetic_energy(state)
+    return energy(state) - kinetic_energy(rho(state), velocity(state))
 
 
 def pressure(state):
@@ -75,3 +74,14 @@ def flux(state):
         result[ndim+1,i] += vel[i]*p
 
     return result
+
+
+def conserved(rho, vel, p):
+    def energy(rho, vel, p):
+        return p/(gamma - 1) + kinetic_energy(rho, vel)
+
+    state = np.empty(nvars)
+    state[0] = rho
+    state[1:nvars-1] = rho*vel
+    state[nvars-1] = energy(rho, vel, p)
+    return state