Question

我有一个大型数据表，其中包含每个ID的事件的开始和结束日期：

library(data.table)
dt = data.table(
    ID = c(1,1,2,2),
    STARTDATE = as.Date(c("2011-10-10","2011-10-13","2011-10-10","2011-10-13"),format = "%Y-%m-%d"),
    ENDDATE = as.Date(c("2011-10-12","2011-10-15","2011-10-12","2011-10-15"),format = "%Y-%m-%d")
)
dt   
>   ID  STARTDATE    ENDDATE
>1:  1 2011-10-10 2011-10-12
>2:  1 2011-10-13 2011-10-15
>3:  2 2011-10-10 2011-10-12
>4:  2 2011-10-13 2011-10-15

我想在时间窗口中为每个ID和日添加行到此数据表，其结果如下：

    STARTDATE    ENDDATE ID      DAILY
1: 2011-10-10 2011-10-12  1 2011-10-10
2: 2011-10-10 2011-10-12  1 2011-10-11
3: 2011-10-10 2011-10-12  1 2011-10-12
4: 2011-10-13 2011-10-15  1 2011-10-13
5: 2011-10-13 2011-10-15  1 2011-10-14
6: 2011-10-13 2011-10-15  1 2011-10-15
7: 2011-10-10 2011-10-12  2 2011-10-10
8: 2011-10-10 2011-10-12  2 2011-10-11
9: 2011-10-10 2011-10-12  2 2011-10-12
10: 2011-10-13 2011-10-15  2 2011-10-13
11: 2011-10-13 2011-10-15  2 2011-10-14
12: 2011-10-13 2011-10-15  2 2011-10-15

我的代码如下：

dt[, cbind(.SD, seq(STARTDATE, ENDDATE, 1)), by = list(STARTDATE, ENDDATE)]

但它不会产生想要的结果：

    STARTDATE    ENDDATE ID         V2
1: 2011-10-10 2011-10-12  1 2011-10-10
2: 2011-10-10 2011-10-12  2 2011-10-11
3: 2011-10-10 2011-10-12  1 2011-10-12
4: 2011-10-13 2011-10-15  1 2011-10-13
5: 2011-10-13 2011-10-15  2 2011-10-14
6: 2011-10-13 2011-10-15  1 2011-10-15
Warnmeldungen:
1: In data.table::data.table(...) :
  Item 1 is of size 2 but maximum size is 3 (recycled leaving remainder of 1 items)
2: In data.table::data.table(...) :
  Item 1 is of size 2 but maximum size is 3 (recycled leaving remainder of 1 items)

它需要某处的ID，但我无法将其输入到数据表的by部分。它给出了另一个错误。有任何想法吗？

Answer 1

这是一个选项。请注意，我们可以使用@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); TextView tv = (TextView)findViewById(R.id.textView); tv.setText("Starting app..."); new Thread(new Runnable() { @Override public void run() { DoIt(); } }).start(); } private void DoIt() { HttpClient httpClient = new DefaultHttpClient(); try { for (int i=1; i<100; i++) { HttpPost request2 = new HttpPost("http://192.168.1.12:3000/bytes/data" + i); HttpResponse response2 = httpClient.execute(request2); // Do something with data. In some cases, it has to download 1MB data } } // catch + finally ... }指定每行的分组，从而生成一个名为by = 1:nrow(dt)的新列。然后，我们可以使用nrow删除该列。

[, nrow := NULL]

R：在data.table中的每个ID的开始日期和结束日期之间插入新的每日行

1 个答案: