feat: creates math calculations for financials

TheAlgorithms · cclauss · Oct 26, 2021 · Oct 24, 2021 · Oct 24, 2021 · Oct 24, 2021
commit ed89816e98b09656763995d5937ce96f1cf4ba17
diff --git a/financials/ABOUT.md b/financials/ABOUT.md
@@ -0,0 +1,12 @@
+## About math calculations
+
+### Interest
+
+* Compound Interest: "Compound interest is calculated by multiplying the initial principal amount by one plus the annual interest rate raised to the number of compound periods minus one." [Compound Interest](https://www.investopedia.com/) 
+* Simple Interest: "Simple interest paid or received over a certain period is a fixed percentage of the principal amount that was borrowed or lent. " [Simple Interest](https://www.investopedia.com/)
+* 
+
+### Average
+
+//todo
+
diff --git a/financials/average.py b/financials/average.py
@@ -0,0 +1,5 @@
+def weighted(ratio,rates):
+    result = 0
+    for index in range(len(ratio)):
+        result = result + ratio[index]*rates[index]
+    return result
diff --git a/financials/interest.py b/financials/interest.py
@@ -0,0 +1,8 @@
+def simple_interest(principle, daily_interest_rate, number_of_days_between_payment):
+    result = principle * daily_interest_rate * number_of_days_between_payment
+    return result
+
+def compound_interest(principle, nominal_annual_interest_rate_percentage , number_of_compounding_periods):
+    result = principle * ((1 + nominal_annual_interest_rate_percentage) ** number_of_compounding_periods - 1)
+    return result
+