Update documentation

tespy/components/components.py

@@ -654,6 +654,18 @@ def zeta_func(self, zeta='', conn=0):
         r"""
         Calculate residual value of :math:`\zeta`-function.
 
+        Parameters
+        ----------
+        zeta : str
+            Component parameter to evaluate the zeta_func on, e. g.
+            :code:`zeta1`.
+
+        conn : int
+            Connection number of inlet and corresponding outlet.
+            In order to use the zeta function, the index of the inlet and
+            the corresponding outlet within the components :code:`ìnl` and
+            :code:`outl` respectively must be identical!
+
         Returns
         -------
         val : float

tespy/components/reactors.py

@@ -179,7 +179,7 @@ class water_electrolyzer(component):
     pressure is 25 bars. The electrolysis efficiency is at 80 % and the
     compressor isentropic efficiency at 85 %. After designing the plant the
     offdesign electrolysis efficiency is predicted by the characteristic line.
-    TODO: LINKTODEFAULTCHAR?
+    The default characteristic line can be found here: :py:mod:`tespy.data`.
 
     >>> fw_el = connection(fw, 'out1', el, 'in2')
     >>> el_o = connection(el, 'out2', oxy, 'in1')