如何使后文件同时使用字符串和数字变量

时间:2019-03-13 08:38:43

标签: stata postfile

我正在尝试编写一个Stata程序,该程序通过标识符进行一些计算,并且希望这样做,以便标识符可以是字符串或整数。

我正在尝试做的一个非常简化的版本是这样的:

clear all

***** test data
input str10 id1 id2 x y
a   1   20  40
a   1   140 20
a   1   0   70
b   2   50  25
b   2   25  50
b   2   40  42
end

*****
capture program drop myprog
program define myprog
    version 14.2
    syntax using, ID(varname) Mean(varname)
    tempname postname

    quietly levelsof `id', local(ids)
    local idtype: type `id'

    postfile `postname' `idtype' `id' `mean' `using', replace


    foreach i of local ids {
        quietly summarize `mean' if `id'==`i'
        post `postname' (`i') (`r(mean)')
    }

    postclose `postname'
end

我希望以下两项都能起作用:

myprog using "test1.dta", id(id1) mean(x)
myprog using "test2.dta", id(id2) mean(x)

有什么建议吗?

2 个答案:

答案 0 :(得分:2)

只需使用if / else语句来区分这两种情况:

capture program drop myprog
program define myprog
    version 14.2
    syntax using, ID(varname) Mean(varname)
    tempname postname

    quietly levelsof `id', local(ids)
    local idtype: type `id'

    postfile `postname' `idtype' `id' `mean' `using', replace

    if substr("`idtype'" , 1, 3) == "str" {
        foreach i of local ids {
            summarize `mean' if `id'=="`i'", meanonly 
            post `postname' ("`i'") (`r(mean)')
        }
    } 
    else {
        foreach i of local ids { 
            summarize `mean' if `id'==`i', meanonly 
            post `postname' (`i') (`r(mean)')       
        }
    }

    postclose `postname'
end

顺便提一下,请注意meanonly的{​​{1}}选项的使用。

答案 1 :(得分:0)

这就是我最终要做的:

capture program drop myprog
program define myprog
    version 14.2
    syntax using, ID(varname) Mean(varname)
    tempname postname

    quietly levelsof `id', local(ids)
    local idtype: type `id'
    postfile `postname' `idtype' `id' `mean' `using', replace

    capture confirm string variable `id'

    if !_rc {
        foreach i of local ids {
            quietly summarize `mean' if `id'=="`i'"
            post `postname' ("`i'") (`r(mean)')
        }
    }
    else {
        foreach i of local ids {
            quietly summarize `mean' if `id'==`i'
            post `postname' (`i') (`r(mean)')
        }
    }

    postclose `postname'
end

两个几乎相同的循环看起来很难看,但是我想那很好。