值得信任
技术支持
我们不仅编写统计方法，我们还会进行验证。
您能从Stata estimator rest与其他估计的比较中看到Monte-Carlo模拟的一致性和覆盖率以及我们统计学家们进行的广
泛测试。每一版的Stata软件，我们都通过了各种认证，包括230万行的代码测试，并产生了430万行的结果输出。我们验
证了这430万行代码中的每一个数字和每一段文字。
Multiple datasets in memory in Stata 16
You can now load multiple datasets into memory. You type
. use people
and people.dta is loaded into memory. Next, you type
. frame create counties
. frame counties: use counties
and you have two datasets in memory. people.dta is in the frame named default, and counties.dta is in the frame named counties. Your current frame is still default. Most Stata commands use the data in the current frame. For example, if you typed
. list
then people.dta will be listed. If you typed
. frame counties: list
then counties.dta will be listed. Or you could make counties the current frame by typing
. frame change counties
and list will now list the counties data.
Navigating frames is easy and so is linking them. Imagine that both datasets have a variable named countycode that identifies counties in the same way. Type
. frlink m:1 countycode, frame(counties)
and each person in the default frame is linked to a county in the counties frame. This means you can now use the frget command to copy variables from the counties frame to the current frame. Or you can use the frval() function to directly access the values of variables in the counties frame. For instance, if we have each individual’s income in the default frame and median county income in the counties frame, we can generate a new variable containing relative income by typing
. generate rel_income = income / frval(counties, median_income)
This is just the beginning. While this example uses only two frames, you can have up to 100 frames in memory at once, and you can have many links among those frames.
Stata 是一套提供其使用者数据分析、数据管理以及绘制专业图表的完整及整合性统计软件。它提供许许多多功能，包含线性混合模型、均衡重复反复及多项式普罗比模式。用Stata绘制的统计图形相当精美。
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