Test cs function with negative values (#14)

* Test cs function with negative values

* Formatting

* Remove numpy 2 check

Author: A-CGray

complexify/cs.py

@@ -5,11 +5,6 @@
 
 import numpy as np
 
-if np.__version__[0] == "2":
-    NumPy2 = True
-else:
-    NumPy2 = False
-
 
 def abs(x):  # noqa: A001
     """

tests/test_cs.py

@@ -9,11 +9,11 @@ class TestComplexSafe(unittest.TestCase):
     def setUp(self):
         # Generate random arrays with a fixed seed
         np.random.seed(3)
-        self.a = np.random.rand(5)
-        self.b = np.random.rand(5)
+        self.a = 2 * (np.random.rand(5) - 0.5)
+        self.b = 2 * (np.random.rand(5) - 0.5)
 
-        self.hFD = 1e-6
-        self.hCS = 1e-40
+        self.hFD = 1e-8
+        self.hCS = 1e-200
 
         self.aFD = self.a.copy()
         self.aFD[0] += self.hFD