主题：分组统计，交叉统计菜单里为什么没有标准差

 测试了一下，就是没有的，如果要是实现标准差等等计算，需要生成表以后重新计算。

 

 

参考代码

 

Dim b As New CrossTableBuilder("统计表1",DataTables("订单"))
b.HGroups.AddDef("客户") '添加客户列用于水平分组
b.VGroups.AddDef("产品","产品_{0}") '添加产品列用于垂直分组,并设置了Pattern参数
b.Totals.AddDef("数量") '添加数量列用于统计
b.Filter="客户 Is not null"

b.Build '生成统计表

For Each r As Row In Tables("统计表1").Rows
    For Each c As Col In Tables("统计表1").Cols
        If c.Name Like "数量*" Then
            Dim drs As List(Of DataRow) = DataTables("订单").Select(b.Filter & " and 客户 = '" & r("客户") & "' and 产品 = '" & c.Caption.Replace("产品_","") & "'")

            '求平均值
            Dim x As Double
            For i As Integer = 0 To drs.Count - 1
                x = x + drs(i)("数量") / drs.count
            Next
            '求平方差
            Dim s2 As Double
            For i As Integer = 0 To drs.Count - 1
                s2 = s2 + (drs(i)("数量") - x) ^ 2 / drs.count
            Next
            Dim s As Double = math.Sqrt(s2)
            r(c.Name) = s
        End If
    Next
Next

MainTable = Tables("统计表1") '打开生成的统计表