我正在 PowerBI 中使用如下所示的数据创建仪表板。数据集由两种类型的数据组成，带有“uom”Pa 和 kg 的数据。是kg的时候，其实是累计数据，我想把它分开。因此，我想创建一个额外的列“delta_value”，它给出了“value”列的不同时间戳之间的差异。 “索引”列是我用来计算索引 i 和索引 i+1 之间差异的列。
我已经能够在 Excel 中执行此操作，这很容易，但我无法在 Power BI 和 DAX 中使用它。
有没有办法编写一个可以做到这一点的措施？
Date and Time,device,value,uom,Index,delta_value
09-07-21 12:02,B,140,Pa,1,
09-07-21 12:00,C,1950,Pa,1,
09-07-21 11:57,D,179,Pa,1,
09-07-21 11:53,E,53,Pa,1,
09-07-21 11:02,B,137,Pa,2,
09-07-21 11:00,C,1947,Pa,2,
09-07-21 10:57,D,184,Pa,2,
09-07-21 10:53,E,53,Pa,2,
09-07-21 10:02,B,141,Pa,3,
09-07-21 9:57,D,173,Pa,3,
09-07-21 9:53,E,49,Pa,3,
09-07-21 9:02,B,137,Pa,4,
09-07-21 9:00,C,1954,Pa,3,
09-07-21 8:57,D,172,Pa,4,
09-07-21 8:53,E,52,Pa,4,
09-07-21 8:02,B,140,Pa,5,
09-07-21 8:00,C,1953,Pa,4,
09-07-21 7:57,D,169,Pa,5,
09-07-21 7:53,E,51,Pa,5,
09-07-21 7:02,B,138,Pa,6,
09-07-21 7:00,C,1951,Pa,5,
09-07-21 6:57,D,177,Pa,6,
09-07-21 6:53,E,46,Pa,6,
09-07-21 6:02,B,141,Pa,7,
09-07-21 5:57,D,180,Pa,7,
09-07-21 5:53,E,51,Pa,7,
09-07-21 5:02,B,142,Pa,8,
09-07-21 5:00,C,1951,Pa,6,
09-07-21 4:56,D,189,Pa,8,
09-07-21 4:53,E,49,Pa,8,
09-07-21 4:02,B,140,Pa,9,
09-07-21 4:00,C,1946,Pa,7,
09-07-21 3:56,D,175,Pa,9,
09-07-21 3:53,E,49,Pa,9,
09-07-21 3:00,C,1950,Pa,8,
09-07-21 1:00,C,1949,Pa,9,
08-07-21 16:06,A,13058,kg,1,9965
07-07-21 1:05,A,3093,kg,2,536
06-07-21 23:05,A,2557,kg,3,807
06-07-21 20:05,A,1750,kg,4,268
06-07-21 19:05,A,1482,kg,5,269
06-07-21 18:05,A,1213,kg,6,536
06-07-21 16:05,A,677,kg,7,268
06-07-21 15:05,A,409,kg,8,396
06-07-21 12:05,A,13,kg,9,0