diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..2d851c9
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,7 @@
+
+reference:
+	amortize -P 100000 -r 0.05 -f monthly -n 36 -s > ref.txt
+
+test:
+	python amort.py -p 100000 -i 5.0 -t 3 -ot "{\"payment_number\":13,\"amount\":5000}"
+
diff --git a/amort.py b/amort.py
index 31827db..df39cef 100644
--- a/amort.py
+++ b/amort.py
@@ -74,10 +74,6 @@ def get_totals(amortization_schedule, func=None):
     return total_paid, total_interest_paid, total_principal_paid
 
 if __name__ == "__main__":
-    # Example usage
-    # principal = 100000
-    # interest_rate = 5.0
-    # loan_term = 3
     def get_arguments():
         p = argparse.ArgumentParser()
         p. add_argument("--principal", "-p", type=float, \
@@ -122,11 +118,6 @@ if __name__ == "__main__":
         print("wrote to file", filename)
 
     principal, interest_rate, loan_term, extra_payments = get_arguments()
-    
-    # one_time_payment = {
-    #     'payment_number': 13,
-    #     'amount': 5000
-    # }
 
     schedule = generate_amortization_schedule(principal, interest_rate, loan_term, extra_payments)
     paid, interest_paid, principal_paid = get_totals(schedule,export)