Update response.py, added tests and corrected the matrices

resolve/re/response.py

@@ -19,17 +19,21 @@ def get_binbounds(coordinates):
 
 
 def convert_polarization(inp, inp_pol, out_pol):
-    mat_stokes_to_circular = jnp.array(
-        [[1, 0, 0, 1], [0, 1, 1j, 0], [0, 1, -1j, 0], [1, 0, 0, -1]]
-    )
-    mat_stokes_to_linear = jnp.array(
-        [[1, 1, 0, 0], [1, -1, 0, 0], [0, 0, 1, 1j], [0, 0, 1, -1j]]
-    )
-    if set(inp_pol) == {"I", "Q", "U", "V"}:
-        if set(out_pol) == {"RR", "RL", "LR", "LL"}:
-            return jnp.tensordot(mat_stokes_to_circular, inp, axes=([0], [0]))
-        elif set(out_pol) == {"XX", "XY", "YX", "YY"}:
-            return jnp.tensordot(mat_stokes_to_linear, inp, axes=([0], [0]))
+    mat_stokes_to_circular = jnp.array([[1,0,0,1],
+                                   [0,1,1,0],
+                                   [0,1j,-1j,0],
+                                   [1,0,0,-1]])
+    mat_stokes_to_linear = jnp.array([[1,1,0,0],
+                                   [1,-1,0,0],
+                                   [0,0,1,1],
+                                   [0,0,1j,-1j]])
+    if inp_pol == ('I', 'Q', 'U', 'V'):
+        if jnp.any(inp[0]**2 < inp[1]**2 + inp[2]**2 + inp[3]**2) or jnp.any(inp[0]) <= 0:
+            raise ValueError('Values for Stokes parameters are inconsistent.')
+        if out_pol == ('RR', 'RL', 'LR', 'LL'):
+            return jnp.tensordot(mat_stokes_to_circular, inp, axes=([0],[0]))
+        elif out_pol == ('XX', 'XY', 'YX', 'YY'):
+            return jnp.tensordot(mat_stokes_to_linear, inp, axes=([0],[0]))
     elif inp_pol == ("I",):
         if out_pol == ("LL", "RR") or out_pol == ("XX", "YY"):
             new_shp = list(inp.shape)