Fix numpy v2 (#298)

Author: BGerwe

impedance/models/circuits/elements.py

@@ -45,6 +45,12 @@ 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/tests/test_circuit_elements.py

@@ -78,7 +78,7 @@ def test_each_element():
     input_vals = [0.1, 0.2, 0.3, 0.4]
     for key, f in circuit_elements.items():
         # don't test the outputs of series and parallel functions
-        if key not in ["s", "p"]:
+        if key not in ["s", "p", "np"]:
             num_inputs = f.num_params
             val = f(input_vals[:num_inputs], freqs)
             assert np.isclose(val, correct_vals[key]).all()

impedance/validation.py

@@ -264,15 +264,15 @@ 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 = 's([R({},{}),'.format([elements[0]], f.tolist())
+    """Builds a circuit of RC elements to be used in LinKK"""
+    circuit_string = f"s([R({[elements[0]]},{f.tolist()}),"
 
-    for (Rk, tk) in zip(elements[1:], ts):
-        circuit_string += f'K({[Rk, tk]},{f.tolist()}),'
+    for Rk, tk in zip(elements[1:], ts):
+        circuit_string += f"K({[Rk, tk]},{f.tolist()}),"
 
-    circuit_string += 'L({},{}),'.format([elements[-1]], f.tolist())
+    circuit_string += f"L({[elements[-1]]},{f.tolist()}),"
     if elements.size == (ts.size + 3):
-        circuit_string += 'C({},{}),'.format([1/elements[-2]], f.tolist())
+        circuit_string += f"C({[1 / elements[-2]]},{f.tolist()}),"
 
     circuit_string = circuit_string.strip(',')
     circuit_string += '])'