From 5fba797d9c9c2478c0abec27d1ee205feb362746 Mon Sep 17 00:00:00 2001
From: Daniel Olsen <daniel.olsen@breakthroughenergy.org>
Date: Fri, 9 Oct 2020 14:24:53 -0700
Subject: [PATCH] feat: add inflation calculator function

---
 powersimdata/design/investment/__init__.py  |  2 +-
 powersimdata/design/investment/inflation.py | 24 +++++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 powersimdata/design/investment/inflation.py

diff --git a/powersimdata/design/investment/__init__.py b/powersimdata/design/investment/__init__.py
index 4590d82cc..68de68755 100644
--- a/powersimdata/design/investment/__init__.py
+++ b/powersimdata/design/investment/__init__.py
@@ -1 +1 @@
-__all__ = ["const", "create_mapping_files", "investment_costs"]
+__all__ = ["const", "create_mapping_files", "inflation", "investment_costs"]
diff --git a/powersimdata/design/investment/inflation.py b/powersimdata/design/investment/inflation.py
new file mode 100644
index 000000000..52f1780ff
--- /dev/null
+++ b/powersimdata/design/investment/inflation.py
@@ -0,0 +1,24 @@
+inflation_rate_pct = {
+    2010: 1.5,
+    2011: 3.0,
+    2012: 1.7,
+    2013: 1.5,
+    2014: 0.8,
+    2015: 0.7,
+    2016: 2.1,
+    2017: 2.1,
+    2018: 1.9,
+    2019: 2.3,
+    2020: 1.3,
+}
+
+
+def calculate_inflation(start_year, end_year):
+    if start_year not in inflation_rate_pct:
+        raise ValueError
+    if (end_year - 1) not in inflation_rate_pct:
+        raise ValueError
+    factor = 1
+    for i in range(start_year, end_year):
+        factor *= 1 + (inflation_rate_pct[i] / 100)
+    return factor