使用权重计算

Question

我有一个数据框，如下所示（Price2变量除外）：

+------+-----------+----------+-------+------+-------------+
| Name |    Day    |   Time   | Price | Size |   Price2    |
+------+-----------+----------+-------+------+-------------+
| A    | 24-Mar-08 | 10:30:01 |     1 |    3 | 0.333333333 |
| A    | 24-Mar-08 | 10:30:01 |     4 |    4 | 1.777777778 |
| A    | 24-Mar-08 | 10:30:01 |     3 |    2 | 0.666666667 |
| A    | 24-Mar-08 | 11:03:12 |     1 |    4 |         0.8 |
| A    | 24-Mar-08 | 11:03:12 |     4 |    1 |         0.8 |
| A    | 25-Mar-08 | 10:30:01 |     3 |    4 |           2 |
| A    | 25-Mar-08 | 10:30:01 |     8 |    2 | 2.666666667 |
| A    | 25-Mar-08 | 11:13:59 |     3 |    2 | 0.428571429 |
| A    | 25-Mar-08 | 11:13:59 |     2 |    4 | 0.571428571 |
| A    | 25-Mar-08 | 11:13:59 |     5 |    5 | 1.785714286 |
| A    | 25-Mar-08 | 11:13:59 |     3 |    3 | 0.642857143 |
| A    | 25-Mar-08 | 11:59:01 |     1 |    5 |           1 |
| B    | 24-Mar-08 | 10:30:01 |     3 |    6 |    2.571429 |
| B    | 24-Mar-08 | 10:30:01 |     4 |    1 |    0.571428 |
| B    | 24-Mar-08 | 11:30:01 |     3 |    2 |           2 |
| B    | 24-Mar-08 | 11:30:01 |     5 |    1 |    1.666667 |
| B    | 25-Mar-08 | 11:30:01 |     7 |    3 | 1.909090909 |
| B    | 25-Mar-08 | 11:30:01 |     4 |    6 | 2.181818182 |
| B    | 25-Mar-08 | 11:30:01 |     2 |    2 | 0.363636364 |
| B    | 25-Mar-08 | 12:00:00 |     6 |    2 |           6 |
+------+-----------+----------+-------+------+-------------+

我想在Stata中计算Price2，Price乘以Size并除以每秒Size的总和。

Answer 1

首先，为每组Name - Day - Time生成一个大小的总和。然后做其余的数学运算 - 将大小乘以价格并除以大小的总和：

bys Name Day Time: egen sumPrice = total(Size) gen Price2 = Price * Size / sumPrice

还要检查一组Name="B"，Day = "24-Mar-08"，Time = "10:30:01"。您示例中的Price2与重新计算的Price2不匹配。其他值匹配。