主题：[求助]有两列分组的表如何求他们的标准差

无法直接统计，需要生成后，循环每一行，然后查询计算的。

http://www.foxtable.com/bbs/dispbbs.asp?BoardID=2&ID=92787&skin=0

代码这样写

Dim g As New GroupTableBuilder("单项指标统计表", DataTables("评价结果"))
g.Groups.AddDef("性别")
g.Groups.AddDef("年级编号")
g.Totals.AddDef("年级编号", AggregateEnum.Count, "人数")
g.Totals.AddDef("身高", AggregateEnum.Average, "身高平均数")
g.Totals.AddDef("身高", AggregateEnum.std, "身高标准差")
g.Totals.AddDef("身高", "身高累计值")
g.Decimals = 2
g.Build()
Dim t As Table = Tables("单项指标统计表")
For Each r As Row In t.Rows
    If r("性别") = "1" Then
        r("性别") = "男"
    Else
        r("性别") = "女"
    End If
    r("身高标准差") = DataTables("评价结果").Compute("StDev(身高)", "年级编号 = '" & r("年级编号") & "'")
Next
MainTable = t

Dim g As New GroupTableBuilder("单项指标统计表", DataTables("评价结果"))
g.Groups.AddDef("性别")
g.Groups.AddDef("年级编号")
g.Totals.AddDef("年级编号", AggregateEnum.Count, "人数")
g.Totals.AddDef("身高", AggregateEnum.Average, "身高平均数")
g.Totals.AddDef("身高", AggregateEnum.std, "身高标准差")
g.Totals.AddDef("身高", "身高累计值")
g.Decimals = 2
g.Build()
Dim t As Table = Tables("单项指标统计表")
For Each r As Row In t.Rows
    r("身高标准差") = DataTables("评价结果").Compute("StDev(身高)", "年级编号 = '" & r("年级编号") & "' and 性别 = '" & r("性别") & "'")

    If r("性别") = "1" Then
        r("性别") = "男"
    Else
        r("性别") = "女"
    End If
Next
MainTable = t