與大熊貓據幀滑動窗口的數據

我有一個數據集，看起來是這樣的：與大熊貓據幀滑動窗口的數據

df = DataFrame(dict(month = [1,2,3,4,5,6], a = [2,4,2,4,2,4], b = [3,5,6,3,4,6]))

我要的是，可以採取一個窗口大小作爲輸入，並給我類似的功能這樣的：

功能：def make_sliding_df(data, size)

如果我做make_sliding_df(df, 1)輸出應該是一個數據幀這樣的：

如果我make_sliding_df(df, 2)輸出應爲一個數據幀這樣的：

我已經嘗試了一堆東西，但目前爲止還沒有人幫助過我，所以我將不勝感激。（我已經檢查了幾個其他類似的問題，但沒有任何幫助）

來源

2017-09-21 ultron

下面是使用shift，applymap和reduce

In [2007]: def make_sliding(df, N): 
     ...:  dfs = [df.shift(-i).applymap(lambda x: [x]) for i in range(0, N+1)] 
     ...:  return reduce(lambda x, y: x.add(y), dfs) 
     ...: 

In [2008]: make_sliding(df, 1) 
Out[2008]: 
      a   b  month 
0 [2, 4.0] [3, 5.0] [1, 2.0] 
1 [4, 2.0] [5, 6.0] [2, 3.0] 
2 [2, 4.0] [6, 3.0] [3, 4.0] 
3 [4, 2.0] [3, 4.0] [4, 5.0] 
4 [2, 4.0] [4, 6.0] [5, 6.0] 
5 [4, nan] [6, nan] [6, nan] 

In [2009]: make_sliding(df, 2) 
Out[2009]: 
       a    b   month 
0 [2, 4.0, 2.0] [3, 5.0, 6.0] [1, 2.0, 3.0] 
1 [4, 2.0, 4.0] [5, 6.0, 3.0] [2, 3.0, 4.0] 
2 [2, 4.0, 2.0] [6, 3.0, 4.0] [3, 4.0, 5.0] 
3 [4, 2.0, 4.0] [3, 4.0, 6.0] [4, 5.0, 6.0] 
4 [2, 4.0, nan] [4, 6.0, nan] [5, 6.0, nan] 
5 [4, nan, nan] [6, nan, nan] [6, nan, nan]

來源

2017-09-21 04:18:52 Zero

這通過使用numpy的一種方式，這可能看起來很醜陋，但它是我第一次嘗試用numpy ...

def make_sliding_df(df,step=1,width=2): 
    l=[] 
    for x in df.columns: 
     a=df[x] 
     a=np.array(a) 
     b=np.append(a,[np.nan]*(width-1)) 
     l.append((b[(np.arange(width)[None, :] + step*np.arange(len(a))[:, None])]).tolist()) 
    newdf=pd.DataFrame(data=l).T 
    newdf.columns=df.columns 
    return(newdf) 

make_sliding_df(df,step=1,width=2) 
Out[157]: 
      a   b  month 
0 [2.0, 4.0] [3.0, 5.0] [1.0, 2.0] 
1 [4.0, 2.0] [5.0, 6.0] [2.0, 3.0] 
2 [2.0, 4.0] [6.0, 3.0] [3.0, 4.0] 
3 [4.0, 2.0] [3.0, 4.0] [4.0, 5.0] 
4 [2.0, 4.0] [4.0, 6.0] [5.0, 6.0] 
5 [4.0, nan] [6.0, nan] [6.0, nan] 

make_sliding_df(df,step=1,width=3) 
Out[158]: 
       a    b   month 
0 [2.0, 4.0, 2.0] [3.0, 5.0, 6.0] [1.0, 2.0, 3.0] 
1 [4.0, 2.0, 4.0] [5.0, 6.0, 3.0] [2.0, 3.0, 4.0] 
2 [2.0, 4.0, 2.0] [6.0, 3.0, 4.0] [3.0, 4.0, 5.0] 
3 [4.0, 2.0, 4.0] [3.0, 4.0, 6.0] [4.0, 5.0, 6.0] 
4 [2.0, 4.0, nan] [4.0, 6.0, nan] [5.0, 6.0, nan] 
5 [4.0, nan, nan] [6.0, nan, nan] [6.0, nan, nan]

來源

2017-09-21 04:38:56 Wen

與大熊貓據幀滑動窗口的數據

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