From a649929475f37501dd028cf1fe7c53d4b468fd32 Mon Sep 17 00:00:00 2001
From: Denis Tereshkin <denis@kasan.ws>
Date: Thu, 20 Dec 2018 21:03:15 +0700
Subject: [PATCH] EquityAnalyzer: optimized algorithm

---
 src/naiback/analyzers/equityanalyzer.py | 29 +++++++++++++++----------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/naiback/analyzers/equityanalyzer.py b/src/naiback/analyzers/equityanalyzer.py
index 3cb447b..b0798a1 100644
--- a/src/naiback/analyzers/equityanalyzer.py
+++ b/src/naiback/analyzers/equityanalyzer.py
@@ -7,6 +7,7 @@ class EquityAnalyzer(Analyzer):
 
     def __init__(self, strategy):
         self.strategy = strategy
+        self.bar_to_pos = []
 
     def get_result(self):
         positions = self.strategy.broker.retired_positions() # TODO also add open positions
@@ -15,7 +16,6 @@ class EquityAnalyzer(Analyzer):
         return equity
 
     def calc_equity(self, positions, bars):
-        timestamp = bars.timestamp
         close = bars.close
 
         cumulative_pnl = 0
@@ -23,16 +23,16 @@ class EquityAnalyzer(Analyzer):
         equity = []
 
         prev_p = 0
-        print(len(close), len(timestamp))
-        for (p,ts) in zip(close, timestamp):
-            active_positions = self.positions_for_timestamp(positions, ts)
+        self.calculate_lookup_table(positions, len(close))
+        for (bar_num, p) in enumerate(close):
+            active_positions = self.positions_for_bar(positions, bar_num)
             for pos in active_positions:
-                if pos.entry_time() == ts:
+                if pos.entry_bar() == bar_num:
                     if pos.is_long():
                         cumulative_pnl += (p - pos.entry_price())
                     else:
                         cumulative_pnl -= (p - pos.entry_price())
-                elif pos.exit_time() == ts:
+                elif pos.exit_bar() == bar_num:
                     if pos.is_long():
                         cumulative_pnl += (pos.exit_price() - prev_p)
                     else:
@@ -47,12 +47,17 @@ class EquityAnalyzer(Analyzer):
             prev_p = p
         return equity
                     
-    def positions_for_timestamp(self, positions, timestamp):
+    def positions_for_bar(self, positions, bar_num):
         result = []
-        for p in positions:
-            if p.entry_time() <= timestamp and p.exit_time() >= timestamp:
-                result.append(p)
+        for pos_index in self.bar_to_pos[bar_num]:
+            pos = positions[pos_index]
+            result.append(pos)
         return result
 
-        
-
+    def calculate_lookup_table(self, positions, length):
+        self.bar_to_pos = []
+        for i in range(0, length):
+            self.bar_to_pos.append([])
+        for pos_index, pos in enumerate(positions):
+            for i in range(pos.entry_bar(), pos.exit_bar() + 1):
+                self.bar_to_pos[i].append(pos_index)