2 files changed, 36 insertions, 0 deletions
diff --git a/finance/equal_principal.py b/finance/equal_principal.py
new file mode 100644
index 0000000..97af5d2
--- /dev/null
+++ b/finance/equal_principal.py
@@ -0,0 +1,17 @@
+
+
+def monthly_analysis(p, r, n):
+    r /= 12
+    paied_p = 0
+    for i in range(n):
+        month_pay = p/n + (p - paied_p)*r
+        print(i, month_pay, p/n, (p-paied_p)*r)
+        paied_p += p/n
+
+
+if __name__ == '__main__':
+
+    p = 2000000
+    r = 0.055
+    n = 30*12
+    monthly_analysis(p, r, n)
diff --git a/finance/equal_principal_interest.py b/finance/equal_principal_interest.py
new file mode 100644
index 0000000..035fd8c
--- /dev/null
+++ b/finance/equal_principal_interest.py
@@ -0,0 +1,19 @@
+
+
+def monthly_analysis(p, r, n):
+    r = r/12
+    month_p_and_i = p*r*(1+r)**n/((1+r)**n - 1)
+    remaining_p = p
+    for i in range(n):
+        month_i = remaining_p*r
+        month_p = month_p_and_i - month_i
+        remaining_p -= month_p
+        print(i, month_p_and_i, month_p, month_i)
+
+
+if __name__ == '__main__':
+    p = 600000
+    r = 0.06
+    n = 20*12
+    monthly_analysis(p, r, n)
+