在 Python 中计算 RSI

Calculating RSI in Python

我正在尝试计算数据帧的 RSI

df = pd.DataFrame({"Close": [100,101,102,103,104,105,106,105,103,102,103,104,103,105,106,107,108,106,105,107,109]})

df["Change"] = df["Close"].diff()

df["Gain"] = np.where(df["Change"]>0,df["Change"],0)

df["Loss"] = np.where(df["Change"]<0,abs(df["Change"]),0 )
df["Index"] = [x for x in range(len(df))]

print(df)

      Close  Change  Gain  Loss  Index
0     100     NaN   0.0   0.0      0
1     101     1.0   1.0   0.0      1
2     102     1.0   1.0   0.0      2
3     103     1.0   1.0   0.0      3
4     104     1.0   1.0   0.0      4
5     105     1.0   1.0   0.0      5
6     106     1.0   1.0   0.0      6
7     105    -1.0   0.0   1.0      7
8     103    -2.0   0.0   2.0      8
9     102    -1.0   0.0   1.0      9
10    103     1.0   1.0   0.0     10
11    104     1.0   1.0   0.0     11
12    103    -1.0   0.0   1.0     12
13    105     2.0   2.0   0.0     13
14    106     1.0   1.0   0.0     14
15    107     1.0   1.0   0.0     15
16    108     1.0   1.0   0.0     16
17    106    -2.0   0.0   2.0     17
18    105    -1.0   0.0   1.0     18
19    107     2.0   2.0   0.0     19
20    109     2.0   2.0   0.0     20


RSI_length = 7

现在卡在计算中了"Avg Gain"。这里平均收益的逻辑是,索引 6 的第一个平均收益将是 "Gain" 的 RSI_length 周期的平均值。对于连续的 "Avg Gain" 它应该是

(Previous Avg Gain * (RSI_length - 1) + "Gain") / RSI_length 

我尝试了以下但没有按预期工作

df["Avg Gain"] = np.nan
df["Avg Gain"] = np.where(df["Index"]==(RSI_length-1),df["Gain"].rolling(window=RSI_length).mean(),\
                          np.where(df["Index"]>(RSI_length-1),(df["Avg Gain"].iloc[df["Index"]-1]*(RSI_length-1)+df["Gain"]) / RSI_length,np.nan))

这段代码的输出是:

print(df)

     Close  Change  Gain  Loss  Index  Avg Gain
0     100     NaN   0.0   0.0      0       NaN
1     101     1.0   1.0   0.0      1       NaN
2     102     1.0   1.0   0.0      2       NaN
3     103     1.0   1.0   0.0      3       NaN
4     104     1.0   1.0   0.0      4       NaN
5     105     1.0   1.0   0.0      5       NaN
6     106     1.0   1.0   0.0      6  0.857143
7     105    -1.0   0.0   1.0      7       NaN
8     103    -2.0   0.0   2.0      8       NaN
9     102    -1.0   0.0   1.0      9       NaN
10    103     1.0   1.0   0.0     10       NaN
11    104     1.0   1.0   0.0     11       NaN
12    103    -1.0   0.0   1.0     12       NaN
13    105     2.0   2.0   0.0     13       NaN
14    106     1.0   1.0   0.0     14       NaN
15    107     1.0   1.0   0.0     15       NaN
16    108     1.0   1.0   0.0     16       NaN
17    106    -2.0   0.0   2.0     17       NaN
18    105    -1.0   0.0   1.0     18       NaN
19    107     2.0   2.0   0.0     19       NaN
20    109     2.0   2.0   0.0     20       NaN

期望的输出是:

    Close  Change   Gain  Loss  Index  Avg Gain
0     100      NaN     0     0      0       NaN
1     101      1.0     1     0      1       NaN
2     102      1.0     1     0      2       NaN
3     103      1.0     1     0      3       NaN
4     104      1.0     1     0      4       NaN
5     105      1.0     1     0      5       NaN
6     106      1.0     1     0      6  0.857143
7     105     -1.0     0     1      7  0.734694
8     103     -2.0     0     2      8  0.629738
9     102     -1.0     0     1      9  0.539775
10    103      1.0     1     0     10  0.605522
11    104      1.0     1     0     11  0.661876
12    103     -1.0     0     1     12  0.567322
13    105      2.0     2     0     13  0.771990
14    106      1.0     1     0     14  0.804563
15    107      1.0     1     0     15  0.832483
16    108      1.0     1     0     16  0.856414
17    106     -2.0     0     2     17  0.734069
18    105     -1.0     0     1     18  0.629202
19    107      2.0     2     0     19  0.825030
20    109      2.0     2     0     20  0.992883

(已编辑)

这是您的公式的一个实现。

RSI_LENGTH = 7

rolling_gain = df["Gain"].rolling(RSI_LENGTH).mean()
df.loc[RSI_LENGTH-1, "RSI"] = rolling_gain[RSI_LENGTH-1]

for inx in range(RSI_LENGTH, len(df)):
    df.loc[inx, "RSI"] = (df.loc[inx-1, "RSI"] * (RSI_LENGTH -1) + df.loc[inx, "Gain"]) / RSI_LENGTH

结果是:

    Close  Change  Gain  Loss  Index       RSI
0     100     NaN   0.0   0.0      0       NaN
1     101     1.0   1.0   0.0      1       NaN
2     102     1.0   1.0   0.0      2       NaN
3     103     1.0   1.0   0.0      3       NaN
4     104     1.0   1.0   0.0      4       NaN
5     105     1.0   1.0   0.0      5       NaN
6     106     1.0   1.0   0.0      6  0.857143
7     105    -1.0   0.0   1.0      7  0.734694
8     103    -2.0   0.0   2.0      8  0.629738
9     102    -1.0   0.0   1.0      9  0.539775
10    103     1.0   1.0   0.0     10  0.605522
11    104     1.0   1.0   0.0     11  0.661876
12    103    -1.0   0.0   1.0     12  0.567322
13    105     2.0   2.0   0.0     13  0.771990
14    106     1.0   1.0   0.0     14  0.804563
15    107     1.0   1.0   0.0     15  0.832483
16    108     1.0   1.0   0.0     16  0.856414
17    106    -2.0   0.0   2.0     17  0.734069
18    105    -1.0   0.0   1.0     18  0.629202
19    107     2.0   2.0   0.0     19  0.825030
20    109     2.0   2.0   0.0     20  0.992883