Fix issues with numpy in circuit string evaluation

impedance/models/circuits/elements.py

@@ -45,12 +45,6 @@ def wrapper(p, f):
             )
         else:
             circuit_elements[func.__name__] = wrapper
-        # Adding numpy to circuit_elements for proper evaluation with
-        # numpy>=2.0.0 because the scalar representation was changed.
-        # "Scalars are now printed as np.float64(3.0) rather than just 3.0."
-        # https://numpy.org/doc/2.0/release/2.0.0-notes.html
-        # #representation-of-numpy-scalars-changed
-        circuit_elements["np"] = np
 
         return wrapper
 

impedance/validation.py

@@ -265,14 +265,18 @@ def fit_linKK(f, ts, M, Z, fit_type='real', add_cap=False):
 
 def eval_linKK(elements, ts, f):
     """Builds a circuit of RC elements to be used in LinKK"""
-    circuit_string = f"s([R({[elements[0]]},{f.tolist()}),"
+    elements_list = elements.tolist()
+    ts_list = ts.tolist()
+    f_list = f.tolist()
 
-    for Rk, tk in zip(elements[1:], ts):
-        circuit_string += f"K({[Rk, tk]},{f.tolist()}),"
+    circuit_string = f"s([R({[elements_list[0]]},{f_list}),"
 
-    circuit_string += f"L({[elements[-1]]},{f.tolist()}),"
-    if elements.size == (ts.size + 3):
-        circuit_string += f"C({[1 / elements[-2]]},{f.tolist()}),"
+    for Rk, tk in zip(elements_list[1:], ts_list):
+        circuit_string += f"K({[Rk, tk]},{f_list}),"
+
+    circuit_string += f"L({[elements_list[-1]]},{f_list}),"
+    if len(elements_list) == (len(ts_list) + 3):
+        circuit_string += f"C({[1 / elements_list[-2]]},{f_list}),"
 
     circuit_string = circuit_string.strip(',')
     circuit_string += '])'