bin_at()bin_at()

将值向下舍入为固定大小的“bin”,并控制 bin 的起点。Rounds values down to a fixed-size "bin", with control over the bin's starting point. (另请参阅 bin function。)(See also bin function.)

语法Syntax

bin_at (Expression, BinSize, FixedPoint)bin_at (Expression, BinSize, FixedPoint)

参数Arguments

  • 表达式:数值类型(包括 datetimetimespan)的标量表达式,指示要舍入的值。Expression: A scalar expression of a numeric type (including datetime and timespan) indicating the value to round.
  • BinSize:与 Expression 类型相同的标量常数,指示每个 bin 的大小。BinSize: A scalar constant of the same type as Expression indicating the size of each bin.
  • FixedPoint:与 Expression 类型相同的标量常数,指示 Expression 的一个值,该值是一个“固定点”(即 bin_at(fixed_point, bin_size, fixed_point) == fixed_point 的一个值 fixed_point) 。FixedPoint: A scalar constant of the same type as Expression indicating one value of Expression which is a "fixed point" (that is, a value fixed_point for which bin_at(fixed_point, bin_size, fixed_point) == fixed_point.)

返回Returns

Expression 下方最接近的 BinSize 倍数,移动后 FixedPoint 将被转换为自身 。The nearest multiple of BinSize below Expression, shifted so that FixedPoint will be translated into itself.

示例Examples

表达式Expression 结果Result 注释Comments
bin_at(6.5, 2.5, 7) 4.5
bin_at(time(1h), 1d, 12h) -12h
bin_at(datetime(2017-05-15 10:20:00.0), 1d, datetime(1970-01-01 12:00:00.0)) datetime(2017-05-14 12:00:00.0) 所有 bin 都将处于中午All bins will be at noon
bin_at(datetime(2017-05-17 10:20:00.0), 7d, datetime(2017-06-04 00:00:00.0)) datetime(2017-05-14 00:00:00.0) 所有 bin 都将在星期日All bins will be on Sundays

在下面的示例中,注意 "fixed point" 参数将作为一个 bin 返回,其他 bin 根据 bin_size 与其对齐。In the following example, notice that the "fixed point" arg is returned as one of the bins and the other bins are aligned to it based on the bin_size. 另请注意,每个日期/时间 bin 表示该 bin 的开始时间:Also note that each datetime bin represents the starting time of that bin:


datatable(Date:datetime, Num:int)[
datetime(2018-02-24T15:14),3,
datetime(2018-02-23T16:14),4,
datetime(2018-02-26T15:14),5]
| summarize sum(Num) by bin_at(Date, 1d, datetime(2018-02-24 15:14:00.0000000)) 
DateDate sum_Numsum_Num
2018-02-23 15:14:00.00000002018-02-23 15:14:00.0000000 44
2018-02-24 15:14:00.00000002018-02-24 15:14:00.0000000 33
2018-02-26 15:14:00.00000002018-02-26 15:14:00.0000000 55