在上述代码中,我们首先加载了第一个数据集 data1.dta,然后使用 merge 1:1 id using data2.dta 命令根据 id 变量进行了一对一匹配合并。合并完成后,Stata 会自动生成一个 _merge 变量来标记合并结果(_merge = 1 表示只存在于主数据集中的观测值,_merge = 2 表示只存在于待合并数据集中的观测值,_merge =...
合并 merge 1:1 make using http://www.stata-press.com/data/r14/autoexpense 2、使用 m:1 webuse dollars,clear webuse sforce 此时使用 1:1 merge 1:1 region using http://www.stata-press.com/data/r14/dollars variable region does not uniquely identify observations in the master data...
Stata merge 的原理 The formal defifinition for merge behavior is the following: Start with the first observation of the master. Find the corresponding observation in the using data, if there is one. Record the matched or unmatched result. Proceed to the next observation in the master dataset. ...
Table 2: Convert Tibble to Data Frame.Looks good!You may have noticed that we have simply stacked the rows of our three data frames on top of each other.In the next example, I’ll explain how to merge our data frames based on a shared ID variable, so keep on reading!
❝ 挖了很久的坑,要来回填了。 ❞首先上韦恩图(Venn Diagram): 无论是 SAS,R,Python,Stata,还是SPSS,关于「merge」(或者是各种形式的「join」,如「inner join」、「Cartesian Product」)数据集的操作…
Merging data, part 2: Multiple-key merges 27 May 2011 William Gould, President Emeritus 4 comments Tweet Multiple-key merges arise when more than one variable is required to uniquely identify the observations in your data. In Merging data, part 1, I discussed single-key merges such as ....
110 (using only) The original data in memory are called the master data. The data in filename.dta are called the using data. After merge, the merged result is left in memory. The id variable is called the key variable. Stata jargon is that the datasets were merged on id. Observations...
Merge(DataTable) Unisce un DataTable specificato e il relativo schema nel DataSetcorrente. Merge(DataSet, Boolean) Unisce un DataSet specificato e il relativo schema nell'DataSetcorrente, mantenendo o rimuovendo eventuali modifiche apportate in questo DataSet in base all'argomento specificato. ...
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To statalist@hsphsun2.harvard.edu Subject Re: st: merge creates duplicates in master data Date Mon, 26 Apr 2010 10:52:37 -0400Doing a match merge when neither master or or using datasets uniquely identify observations rarely makes sense. I think the update option only makes sense on a on...