从pandas DataFrame计算RSI指标?

时间:2019-07-12 11:51:12

标签: python pandas dataframe

我的问题

我在 Github 上尝试了很多库,但是它们都没有为 TradingView 生成匹配的结果,因此我按照此link上的公式计算了 RSI 指示器。我使用 Excel 进行了计算,并使用 TradingView 整理了结果。我知道它是绝对正确,但是我没有找到使用 Pandas 进行计算的方法。

公式

              100
RSI = 100 - --------
             1 + RS

RS = Average Gain / Average Loss

The very first calculations for average gain and average loss are simple
14-period averages:

First Average Gain = Sum of Gains over the past 14 periods / 14.
First Average Loss = Sum of Losses over the past 14 periods / 14

The second, and subsequent, calculations are based on the prior averages
and the current gain loss:

Average Gain = [(previous Average Gain) x 13 + current Gain] / 14.
Average Loss = [(previous Average Loss) x 13 + current Loss] / 14.

预期结果

     close   change     gain     loss     avg_gian    avg_loss        rs  \
0    4724.89      NaN      NaN      NaN          NaN         NaN       NaN   
1    4378.51  -346.38     0.00   346.38          NaN         NaN       NaN   
2    6463.00  2084.49  2084.49     0.00          NaN         NaN       NaN   
3    9838.96  3375.96  3375.96     0.00          NaN         NaN       NaN   
4   13716.36  3877.40  3877.40     0.00          NaN         NaN       NaN   
5   10285.10 -3431.26     0.00  3431.26          NaN         NaN       NaN   
6   10326.76    41.66    41.66     0.00          NaN         NaN       NaN   
7    6923.91 -3402.85     0.00  3402.85          NaN         NaN       NaN   
8    9246.01  2322.10  2322.10     0.00          NaN         NaN       NaN   
9    7485.01 -1761.00     0.00  1761.00          NaN         NaN       NaN   
10   6390.07 -1094.94     0.00  1094.94          NaN         NaN       NaN   
11   7730.93  1340.86  1340.86     0.00          NaN         NaN       NaN   
12   7011.21  -719.72     0.00   719.72          NaN         NaN       NaN   
13   6626.57  -384.64     0.00   384.64          NaN         NaN       NaN   
14   6371.93  -254.64     0.00   254.64   931.605000  813.959286  1.144535   
15   4041.32 -2330.61     0.00  2330.61   865.061786  922.291480  0.937948   
16   3702.90  -338.42     0.00   338.42   803.271658  880.586374  0.912201   
17   3434.10  -268.80     0.00   268.80   745.895111  836.887347  0.891273   
18   3813.69   379.59   379.59     0.00   719.730460  777.109680  0.926163   
19   4103.95   290.26   290.26     0.00   689.053999  721.601845  0.954895   
20   5320.81  1216.86  1216.86     0.00   726.754428  670.058856  1.084613   
21   8555.00  3234.19  3234.19     0.00   905.856968  622.197509  1.455899   
22  10854.10  2299.10  2299.10     0.00  1005.374328  577.754830  1.740140   

       rsi_14  
0         NaN  
1         NaN  
2         NaN  
3         NaN  
4         NaN  
5         NaN  
6         NaN  
7         NaN  
8         NaN  
9         NaN  
10        NaN  
11        NaN  
12        NaN  
13        NaN  
14  53.369848  
15  48.399038  
16  47.704239  
17  47.125561  
18  48.083322  
19  48.846358  
20  52.029461  
21  59.281719  
22  63.505515  

我的代码

导入

import pandas as pd
import numpy as np

加载数据

df = pd.read_csv("rsi_14_test_data.csv")
close = df['close']
print(close)

0      4724.89
1      4378.51
2      6463.00
3      9838.96
4     13716.36
5     10285.10
6     10326.76
7      6923.91
8      9246.01
9      7485.01
10     6390.07
11     7730.93
12     7011.21
13     6626.57
14     6371.93
15     4041.32
16     3702.90
17     3434.10
18     3813.69
19     4103.95
20     5320.81
21     8555.00
22    10854.10
Name: close, dtype: float64

更改

计算每行的更改

change = close.diff(1)
print(change)

0         NaN
1     -346.38
2     2084.49
3     3375.96
4     3877.40
5    -3431.26
6       41.66
7    -3402.85
8     2322.10
9    -1761.00
10   -1094.94
11    1340.86
12    -719.72
13    -384.64
14    -254.64
15   -2330.61
16    -338.42
17    -268.80
18     379.59
19     290.26
20    1216.86
21    3234.19
22    2299.10
Name: close, dtype: float64

盈亏

从变化中获得收益和损失

is_gain, is_loss = change > 0, change < 0
gain, loss = change, -change
gain[is_loss] = 0
loss[is_gain] = 0
​
gain.name = 'gain'
loss.name = 'loss'
print(loss)

0         NaN
1      346.38
2        0.00
3        0.00
4        0.00
5     3431.26
6        0.00
7     3402.85
8        0.00
9     1761.00
10    1094.94
11       0.00
12     719.72
13     384.64
14     254.64
15    2330.61
16     338.42
17     268.80
18       0.00
19       0.00
20       0.00
21       0.00
22       0.00
Name: loss, dtype: float64

计算拳头平均损益

前n行的平均值

n = 14
avg_gain = change * np.nan
avg_loss = change * np.nan
​
avg_gain[n] = gain[:n+1].mean()
avg_loss[n] = loss[:n+1].mean()
​
avg_gain.name = 'avg_gain'
avg_loss.name = 'avg_loss'
​
avg_df = pd.concat([gain, loss, avg_gain, avg_loss], axis=1)
print(avg_df)

       gain     loss  avg_gain    avg_loss
0       NaN      NaN       NaN         NaN
1      0.00   346.38       NaN         NaN
2   2084.49     0.00       NaN         NaN
3   3375.96     0.00       NaN         NaN
4   3877.40     0.00       NaN         NaN
5      0.00  3431.26       NaN         NaN
6     41.66     0.00       NaN         NaN
7      0.00  3402.85       NaN         NaN
8   2322.10     0.00       NaN         NaN
9      0.00  1761.00       NaN         NaN
10     0.00  1094.94       NaN         NaN
11  1340.86     0.00       NaN         NaN
12     0.00   719.72       NaN         NaN
13     0.00   384.64       NaN         NaN
14     0.00   254.64   931.605  813.959286
15     0.00  2330.61       NaN         NaN
16     0.00   338.42       NaN         NaN
17     0.00   268.80       NaN         NaN
18   379.59     0.00       NaN         NaN
19   290.26     0.00       NaN         NaN
20  1216.86     0.00       NaN         NaN
21  3234.19     0.00       NaN         NaN
22  2299.10     0.00       NaN         NaN

对于平均增益和平均损耗的第一个计算是可以的,但是我不知道如何对第二个应用pandas.core.window.Rolling.apply,以及随后的应用,因为它们位于许多行和不同的列中。 可能是这样的:

avg_gain[n] = (avg_gain[n-1]*13 + gain[n]) / 14

我的愿望-我的问题

  • 计算和使用技术指标的最佳方法?
  • 以“ Pandas样式”完成上述代码。
  • 与熊猫相比,传统的循环编码方式是否会降低性能?

4 个答案:

答案 0 :(得分:2)

平均损益由递归公式计算,该公式不能用numpy向量化。但是,我们可以尝试找到一种 analytical (即非递归)解决方案来计算各个元素。然后可以使用numpy来实现这种解决方案。

将平均增益表示为y,将当前增益表示为x,得到y[i] = a*y[i-1] + b*x[i],其中a = 13/14b = 1/14代表n = 14 。展开递归会导致: enter image description here (抱歉图片,键入起来很麻烦)

可以使用cumsum以有效的方式以numpy计算(rma =运行移动平均线):

import pandas as pd
import numpy as np

df = pd.DataFrame({'close':[4724.89, 4378.51,6463.00,9838.96,13716.36,10285.10,
                          10326.76,6923.91,9246.01,7485.01,6390.07,7730.93,
                          7011.21,6626.57,6371.93,4041.32,3702.90,3434.10,
                          3813.69,4103.95,5320.81,8555.00,10854.10]})
n = 14

def rma(x, n, y0):
    a = (n-1) / n
    ak = a**np.arange(len(x)-1, -1, -1)
    return np.append(y0, np.cumsum(ak * x) / ak / n + y0 * a**np.arange(1, len(x)+1))

df['change'] = df['close'].diff()
df['gain'] = df.change.mask(df.change < 0, 0.0)
df['loss'] = -df.change.mask(df.change > 0, -0.0)
df.loc[n:,'avg_gain'] = rma( df.gain[n+1:].values, n, df.loc[:n, 'gain'].mean())
df.loc[n:,'avg_loss'] = rma( df.loss[n+1:].values, n, df.loc[:n, 'loss'].mean())
df['rs'] = df.avg_gain / df.avg_loss
df['rsi_14'] = 100 - (100 / (1 + df.rs))

df.round(2)的输出:

         close   change     gain     loss  avg_gain  avg_loss    rs    rsi  rsi_14
0      4724.89      NaN      NaN      NaN       NaN       NaN   NaN    NaN     NaN
1      4378.51  -346.38     0.00   346.38       NaN       NaN   NaN    NaN     NaN
2      6463.00  2084.49  2084.49     0.00       NaN       NaN   NaN    NaN     NaN
3      9838.96  3375.96  3375.96     0.00       NaN       NaN   NaN    NaN     NaN
4     13716.36  3877.40  3877.40     0.00       NaN       NaN   NaN    NaN     NaN
5     10285.10 -3431.26     0.00  3431.26       NaN       NaN   NaN    NaN     NaN
6     10326.76    41.66    41.66     0.00       NaN       NaN   NaN    NaN     NaN
7      6923.91 -3402.85     0.00  3402.85       NaN       NaN   NaN    NaN     NaN
8      9246.01  2322.10  2322.10     0.00       NaN       NaN   NaN    NaN     NaN
9      7485.01 -1761.00     0.00  1761.00       NaN       NaN   NaN    NaN     NaN
10     6390.07 -1094.94     0.00  1094.94       NaN       NaN   NaN    NaN     NaN
11     7730.93  1340.86  1340.86     0.00       NaN       NaN   NaN    NaN     NaN
12     7011.21  -719.72     0.00   719.72       NaN       NaN   NaN    NaN     NaN
13     6626.57  -384.64     0.00   384.64       NaN       NaN   NaN    NaN     NaN
14     6371.93  -254.64     0.00   254.64    931.61    813.96  1.14  53.37   53.37
15     4041.32 -2330.61     0.00  2330.61    865.06    922.29  0.94  48.40   48.40
16     3702.90  -338.42     0.00   338.42    803.27    880.59  0.91  47.70   47.70
17     3434.10  -268.80     0.00   268.80    745.90    836.89  0.89  47.13   47.13
18     3813.69   379.59   379.59     0.00    719.73    777.11  0.93  48.08   48.08
19     4103.95   290.26   290.26     0.00    689.05    721.60  0.95  48.85   48.85
20     5320.81  1216.86  1216.86     0.00    726.75    670.06  1.08  52.03   52.03
21     8555.00  3234.19  3234.19     0.00    905.86    622.20  1.46  59.28   59.28
22    10854.10  2299.10  2299.10     0.00   1005.37    577.75  1.74  63.51   63.51


关于性能的最后一个问题: python / pandas中的显式循环很糟糕,请尽可能避免使用。如果不能,请尝试cython or numba

为了说明这一点,我对numpy解决方案与dimitris_ps'loop solution进行了较小的比较:

import pandas as pd
import numpy as np
import timeit

mult = 1        # length of dataframe = 23 * mult
number = 1000   # number of loop for timeit

df0 = pd.DataFrame({'close':[4724.89, 4378.51,6463.00,9838.96,13716.36,10285.10,
                          10326.76,6923.91,9246.01,7485.01,6390.07,7730.93,
                          7011.21,6626.57,6371.93,4041.32,3702.90,3434.10,
                          3813.69,4103.95,5320.81,8555.00,10854.10] * mult })
n = 14

def rsi_np():
    # my numpy solution from above
    return df

def rsi_loop():
    # loop solution https://stackoverflow.com/a/57008625/3944322
    # without the wrong alternative calculation of df['avg_gain'][14]
    return df

df = df0.copy()
time_np = timeit.timeit('rsi_np()', globals=globals(), number = number) / 1000 * number

df = df0.copy()
time_loop = timeit.timeit('rsi_loop()', globals=globals(), number = number) / 1000 * number

print(f'rows\tnp\tloop\n{len(df0)}\t{time_np:.1f}\t{time_loop:.1f}')

assert np.allclose(rsi_np(), rsi_loop(), equal_nan=True)

结果(毫秒/循环):

rows    np    loop
23      4.9   9.2
230     5.0   112.3
2300    5.5   1122.7

因此,即使对于8行(第15 ... 22行),循环求解所花费的时间也是numpy解决方案的两倍。 Numpy可很好地扩展,而循环解决方案不适用于大型数据集。

答案 1 :(得分:1)

这里是一个选项。

我只会触摸你的第二颗子弹

# libraries required
import pandas as pd
import numpy as np

# create dataframe
df = pd.DataFrame({'close':[4724.89, 4378.51,6463.00,9838.96,13716.36,10285.10,
                          10326.76,6923.91,9246.01,7485.01,6390.07,7730.93,
                          7011.21,6626.57,6371.93,4041.32,3702.90,3434.10,
                          3813.69,4103.95,5320.81,8555.00,10854.10]})

df['change'] = df['close'].diff(1) # Calculate change

# calculate gain / loss from every change
df['gain'] = np.select([df['change']>0, df['change'].isna()], 
                       [df['change'], np.nan], 
                       default=0) 
df['loss'] = np.select([df['change']<0, df['change'].isna()], 
                       [-df['change'], np.nan], 
                       default=0)

# create avg_gain /  avg_loss columns with all nan
df['avg_gain'] = np.nan 
df['avg_loss'] = np.nan

n = 14 # what is the window

# keep first occurrence of rolling mean
df['avg_gain'][n] = df['gain'].rolling(window=n).mean().dropna().iloc[0] 
df['avg_loss'][n] = df['loss'].rolling(window=n).mean().dropna().iloc[0]
# Alternatively
df['avg_gain'][n] = df.loc[:n, 'gain'].mean()
df['avg_loss'][n] = df.loc[:n, 'loss'].mean()

# This is not a pandas way, looping through the pandas series, but it does what you need
for i in range(n+1, df.shape[0]):
    df['avg_gain'].iloc[i] = (df['avg_gain'].iloc[i-1] * (n - 1) + df['gain'].iloc[i]) / n
    df['avg_loss'].iloc[i] = (df['avg_loss'].iloc[i-1] * (n - 1) + df['loss'].iloc[i]) / n

# calculate rs and rsi
df['rs'] = df['avg_gain'] / df['avg_loss']
df['rsi'] = 100 - (100 / (1 + df['rs'] ))

答案 2 :(得分:0)

还有一种更简单的方法,即talib软件包。

import talib   
close = df['close']
rsi = talib.RSI(close, timeperiod=14)

如果您希望Bollinger Bands使用RSI也很容易。

upperBB, middleBB, lowerBB = talib.BBANDS(close, timeperiod=20, nbdevup=2, nbdevdn=2, matype=0)

您可以在RSI上使用布林带,而不是固定参考水平70和30。

upperBBrsi, MiddleBBrsi, lowerBBrsi = talib.BBANDS(rsi, timeperiod=50, nbdevup=2, nbdevdn=2, matype=0)

最后,您可以使用%b钙化对RSI进行归一化。

normrsi = (rsi - lowerBBrsi) / (upperBBrsi - lowerBBrsi)

关于Talib的信息 https://mrjbq7.github.io/ta-lib/

布林带的信息 https://www.BollingerBands.com

答案 3 :(得分:0)

好的,这里是圣诞老人: 这是 rsi 代码,替换所有带有“aa”的东西:

import pandas as pd
rsi_period = 14
df = pd.Series(coinaalist)
chg = df.diff(1)
gain = chg.mask(chg<0,0)
loss = chg.mask(chg>0,0)
avg_gain = gain.ewm(com = rsi_period-1,min_periods=rsi_period).mean()
avg_loss = loss.ewm(com = rsi_period-1,min_periods=rsi_period).mean()
rs = abs(avg_gain / avg_loss)
crplaa = 100 - (100/(1+rs))
coinaarsi = crplaa.iloc[-1]