[GH-139] Add Awesome Oscillator

The AO indicator is a good indicator for measuring the market dynamics,
it reflects specific changes in the driving force of the market, which
helps to identify the strength of the trend, including the points of
its formation and reversal.

Awesome Oscillator Formula

* MEDIAN PRICE = (HIGH+LOW)/2
* AO = SMA(MEDIAN PRICE, 5)-SMA(MEDIAN PRICE, 34)

Examples:
* `df['ao']` returns the Awesome Oscillator with default windows (5, 34)
* `df['ao_3,10']` returns the Awesome Oscillator with a window of 3 and 10

README.md

@@ -4,7 +4,7 @@
 [![codecov](https://codecov.io/gh/jealous/stockstats/branch/master/graph/badge.svg?token=IFMD1pVJ7T)](https://codecov.io/gh/jealous/stockstats)
 [![pypi](https://img.shields.io/pypi/v/stockstats.svg)](https://pypi.python.org/pypi/stockstats)
 
-VERSION: 0.5.3
+VERSION: 0.5.4
 
 ## Introduction
 
@@ -56,6 +56,7 @@ Supported statistics/indicators are:
 * Supertrend: with the Upper Band and Lower Band
 * Aroon: Aroon Oscillator
 * Z: Z-Score
+* AO: Awesome Oscillator
 
 ## Installation
 
@@ -693,6 +694,22 @@ Where:
 Examples:
 * `df['close_75_z']` returns the Z-Score of close price with a window of 75
 
+#### [Awesome Oscillator](https://www.ifcm.co.uk/ntx-indicators/awesome-oscillator)
+
+The AO indicator is a good indicator for measuring the market dynamics,
+it reflects specific changes in the driving force of the market, which
+helps to identify the strength of the trend, including the points of
+its formation and reversal.
+
+Awesome Oscillator Formula
+
+* MEDIAN PRICE = (HIGH+LOW)/2
+* AO = SMA(MEDIAN PRICE, 5)-SMA(MEDIAN PRICE, 34)
+
+Examples:
+* `df['ao']` returns the Awesome Oscillator with default windows (5, 34)
+* `df['ao_3,10']` returns the Awesome Oscillator with a window of 3 and 10
+
 ## Issues
 
 We use [Github Issues](https://github.com/jealous/stockstats/issues) to track

stockstats.py

@@ -105,6 +105,9 @@ class StockDataFrame(pd.DataFrame):
     KAMA_SLOW = 34
     KAMA_FAST = 5
 
+    AO_SLOW = 34
+    AO_FAST = 5
+
     MULTI_SPLIT_INDICATORS = ("kama",)
 
     # End of options
@@ -548,32 +551,33 @@ def _get_supertrend(self, window=None):
         m_atr = self.SUPERTREND_MUL * self._atr(window)
         hl_avg = (high + low) / 2.0
         # basic upper band
-        b_ub = hl_avg + m_atr
+        b_ub = list(hl_avg + m_atr)
         # basic lower band
-        b_lb = hl_avg - m_atr
+        b_lb = list(hl_avg - m_atr)
 
         size = len(close)
         ub = np.empty(size, dtype=np.float64)
         lb = np.empty(size, dtype=np.float64)
         st = np.empty(size, dtype=np.float64)
+        close = list(close)
 
         for i in range(size):
             if i == 0:
-                ub[i] = b_ub.iloc[i]
-                lb[i] = b_lb.iloc[i]
-                if close.iloc[i] <= ub[i]:
+                ub[i] = b_ub[i]
+                lb[i] = b_lb[i]
+                if close[i] <= ub[i]:
                     st[i] = ub[i]
                 else:
                     st[i] = lb[i]
                 continue
 
-            last_close = close.iloc[i - 1]
-            curr_close = close.iloc[i]
+            last_close = close[i - 1]
+            curr_close = close[i]
             last_ub = ub[i - 1]
             last_lb = lb[i - 1]
             last_st = st[i - 1]
-            curr_b_ub = b_ub.iloc[i]
-            curr_b_lb = b_lb.iloc[i]
+            curr_b_ub = b_ub[i]
+            curr_b_lb = b_lb[i]
 
             # calculate current upper band
             if curr_b_ub < last_ub or last_close > last_ub:
@@ -1170,6 +1174,35 @@ def _get_mfi(self, window=None):
         mfi.iloc[:window] = 0.5
         self[column_name] = mfi
 
+    def _get_ao(self, windows=None):
+        """ get awesome oscillator
+
+        The AO indicator is a good indicator for measuring the market dynamics,
+        it reflects specific changes in the driving force of the market, which
+        helps to identify the strength of the trend, including the points of
+        its formation and reversal.
+
+
+        Awesome Oscillator Formula
+        * MEDIAN PRICE = (HIGH+LOW)/2
+        * AO = SMA(MEDIAN PRICE, 5)-SMA(MEDIAN PRICE, 34)
+
+        https://www.ifcm.co.uk/ntx-indicators/awesome-oscillator
+        """
+        if windows is None:
+            fast = self.AO_FAST
+            slow = self.AO_SLOW
+            column_name = 'ao'
+        else:
+            n0, n1 = self.to_ints(windows)
+            fast = min(n0, n1)
+            slow = max(n0, n1)
+            column_name = 'ao_{},{}'.format(fast, slow)
+
+        median_price = (self['high'] + self['low']) * 0.5
+        ao = self._sma(median_price, fast) - self._sma(median_price, slow)
+        self[column_name] = ao
+
     def _get_kama(self, column, windows, fasts=None, slows=None):
         """ get Kaufman's Adaptive Moving Average.
         Implemented after
@@ -1200,17 +1233,18 @@ def _get_kama(self, column, windows, fasts=None, slows=None):
         slow_ema_smoothing = 2.0 / (slow + 1)
         smoothing_2 = fast_ema_smoothing - slow_ema_smoothing
         efficient_smoothing = efficiency_ratio * smoothing_2
-        smoothing = 2 * (efficient_smoothing + slow_ema_smoothing)
+        smoothing = list(2 * (efficient_smoothing + slow_ema_smoothing))
 
         # start with simple moving average
-        kama = self._sma(col, window)
+        kama = list(self._sma(col, window))
+        col_list = list(col)
         if len(kama) >= window:
-            last_kama = kama.iloc[window - 1]
+            last_kama = kama[window - 1]
         else:
             last_kama = 0.0
         for i in range(window, len(kama)):
-            cur = smoothing.iloc[i] * (col.iloc[i] - last_kama) + last_kama
-            kama.iloc[i] = cur
+            cur = smoothing[i] * (col_list[i] - last_kama) + last_kama
+            kama[i] = cur
             last_kama = cur
         self[column_name] = kama
 
@@ -1347,6 +1381,7 @@ def handler(self):
              'supertrend_lb',
              'supertrend_ub'): self._get_supertrend,
             ('aroon',): self._get_aroon,
+            ('ao',): self._get_ao,
         }
 
     def __init_not_exist_column(self, key):

test.py

@@ -671,6 +671,16 @@ def test_supertrend(self):
         assert_that(st_ub[idx], near_to(14.6457))
         assert_that(st_lb[idx], near_to(12.9021))
 
+    def test_ao(self):
+        stock = self.get_stock_90day()
+        ao = stock['ao']
+        ao1 = stock['ao_5,34']
+        ao2 = stock['ao_5,10']
+        idx = 20110302
+        assert_that(ao[idx], near_to(-0.112))
+        assert_that(ao1[idx], equal_to(ao[idx]))
+        assert_that(ao2[idx], near_to(-0.071))
+
     def test_drop_column_inplace(self):
         stock = self._supor[:20]
         stock.columns.name = 'Luke'