diff --git a/ampdlib/ampdlib.py b/ampdlib/ampdlib.py
index 544042b..d16eb40 100644
--- a/ampdlib/ampdlib.py
+++ b/ampdlib/ampdlib.py
@@ -144,7 +144,7 @@ def ampd_fast(sig_input:np.ndarray, window_length:int, hop_length:int=None, lsm_
 
 	# Define iterations
 	if window_length < sig_input.shape[0]:
-		iterations = (sig_input.shape[0] - window_length) / hop_length + 1
+		iterations = int((sig_input.shape[0] - window_length) // hop_length) + 1
 		if hop_length is None:
 			hop_length = window_length
 	else:
diff --git a/ampdlib/tests/test.py b/ampdlib/tests/test.py
index 0558418..e297d73 100644
--- a/ampdlib/tests/test.py
+++ b/ampdlib/tests/test.py
@@ -3,30 +3,64 @@
 __copyright__   = "Copyright 2022, Luca Cerina"
 __email__       = "lccerina@gmail.com"
 
-import sys
-from time import perf_counter
+# import sys
+# from time import perf_counter
+# import numpy as np
+# from scipy.io import loadmat
+# sys.path.append('../')
+# import ampdLib
+
+# if __name__ == "__main__":
+#     print("Loading data")
+#     real_data = loadmat('data.mat')
+
+#     print("Find peaks")
+#     N = 30000
+#     input_data = real_data['ecg_signal'][0:N,0].flatten()
+#     tStart = perf_counter()
+#     ampd_peaks = ampdLib.ampd_fast(input_data)
+#     tEnd = perf_counter()
+#     print("Samples: {}".format(N))
+#     print("Peaks found in: {} seconds".format(tEnd-tStart))
+
+#     print("Test results")
+#     # Find misplaced peaks
+#     error_peaks = np.sum((ampd_peaks - real_data['real_peaks'][0][0:ampd_peaks.shape[0]]) != 0)
+#     if(error_peaks == 0):
+#         print("Test passed")
+#     else:
+#         print("Total error {}".format(error_peaks))
+
+import unittest
+
+import ampdlib
 import numpy as np
 from scipy.io import loadmat
-sys.path.append('../')
-import ampdLib
+
+
+class TestLibrary(unittest.TestCase):
+    def setUp(self) -> None:
+        print("Loading data")
+        self.test_data = loadmat('data.mat')
+        N = 30000
+        self.input_data = self.test_data['ecg_signal'][0:N,0].flatten()
+        self.real_peaks = self.test_data['real_peaks'][0]
+        return super().setUp()
+
+    def test_detection(self):
+        ampd_peaks = ampdlib.ampd_fast(self.input_data, window_length=2000, hop_length=1000)
+        error_peaks = np.sum((ampd_peaks - self.real_peaks[0:ampd_peaks.shape[0]]) != 0)
+        self.assertEqual(error_peaks, 0)
+
+    def test_assertions(self):
+        with self.assertRaises(AssertionError):
+            ampdlib.ampd(self.input_data, lsm_limit=-1)
+        with self.assertRaises(AssertionError):
+            ampdlib.ampd(self.input_data, lsm_limit=2)
+        with self.assertRaises(AssertionError):
+            ampdlib.ampd_fast(self.input_data, 2000, -1)
+        with self.assertRaises(AssertionError):
+            ampdlib.ampd_fast(self.input_data, 2000, 2100)
 
 if __name__ == "__main__":
-    print("Loading data")
-    real_data = loadmat('data.mat')
-
-    print("Find peaks")
-    N = 30000
-    input_data = real_data['ecg_signal'][0:N,0].flatten()
-    tStart = perf_counter()
-    ampd_peaks = ampdLib.ampd_fast(input_data)
-    tEnd = perf_counter()
-    print("Samples: {}".format(N))
-    print("Peaks found in: {} seconds".format(tEnd-tStart))
-
-    print("Test results")
-    # Find misplaced peaks
-    error_peaks = np.sum((ampd_peaks - real_data['real_peaks'][0][0:ampd_peaks.shape[0]]) != 0)
-    if(error_peaks == 0):
-        print("Test passed")
-    else:
-        print("Total error {}".format(error_peaks))
+    unittest.main()
\ No newline at end of file