Import data from SAS and SPSS
With Stata 16’s new import sas and import spss commands, you can now import data stored in SAS (.sas7bdat) and SPSS (.sav) formats. The dialog boxes make it easy to explore the data before importing them and, if desired, to select a subset of variables and observations to load into Stata.
In addition, with the new import sasxport8 and export sasxport8 commands, you can import and export SAS XPORT Version 8 Transport files into Stata. The existing import sasxport and export sasxport commands worked with SAS XPORT Version 5 Transport files and have been renamed import sasxport5 and export sasxport5.
Stata 16 New in Bayesian analysis—Multiple chains, predictions, and more
Multiple chains.
Bayesian inference based on an MCMC (Markov chain Monte Carlo) sample is valid only if the Markov chain has converged. One way we can evaluate this convergence is to simulate and compare multiple chains.
The new nchains() option can be used with both the bayes: prefix and the bayesmh command. For instance, you type
. bayes, nchains(4): regress y x1 x2
and four chains will be produced. The chains will be combined to produce a more accurate final result. Before interpreting the result, however, you can compare the chains graphically to evaluate convergence. You can also evaluate convergence using the Gelman–Rubin convergence diagnostic that is now reported by bayes: regress and other Bayesian estimation commands when multiple chains are simulated. When you are concerned about noncovergence, you can investigate further using the bayesstats grubin command to obtain individual Gelman–Rubin diagnostics for each parameter in your model.
Bayesian predictions.
Bayesian predictions are simulated values from the posterior predictive distribution. These predictions are useful for checking model fit and for predicting out-of-sample observations. After you fit a model with bayesmh, you can use bayespredict to compute these simulated values or functions of them and save those in a new Stata dataset. For instance, you can type
. bayespredict (ymin:@min({_ysim})) (ymax:@max({_ysim})), saving(yminmax)
to compute minimums and maximums of the simulated values. You can then use other postestimation commands such as bayesgraph to obtain summaries of the predictions.
The dataset created by bayespredict may include thousands of simulated values for each observation in your dataset. Sometimes, you do not need all of these individual values. To instead obtain posterior summaries such as posterior means or medians, you can use bayespredict, pmean or bayespredict, pmedian. Alternatively, you may be interested in a random sample of the simulated values. You can use, for instance, bayesreps, nreps(100) to obtain 100 replicates.
Finally, you may want to evaluate model goodness of fit using posterior predictive p-values, also known as PPPs or as Bayesian predictive p-values. PPPs measure agreement between observed and replicated data and can be computed using the new bayesstats ppvalues command. For instance, using our earlier example
. bayesstats ppvalues {ymin} {ymax} using yminmax
Stata是一款完整的、集成的统计软件包，提供您需要的一切数据分析、数据管理和图形。
快速,简单并易于使用
点击式的界面和强大,直观的命令语言让Stata使用起来快速,精确并易于使用。
所有的分析结果都可以被复制和存档，并用来出版和审查。不管您什么时候写的内容，版本控制系统确保统计程序可继续生成同样的结果。
统计功能介绍
Stata使得大量的统计工具用于指尖
标准方法，如
基本表格和总结
案例对照分析
ARIMA
ANOVA 和MANOVA
线性回归
时间序列平滑
广义线性模型（GLM）
聚类分析
对比和比较
功率分析
样本选择
……
高级方法，如
当Stata执行您的分析或理解使用的方法时，Stata不会让您孤立无援或订购很多书籍来了解每个细节。
我们每一个数据管理功能都有完整的解释，并记录在案，并在实践中显示实际的例子。每一个估计都有完全记录，包含几个真实数据的例子，真正讨论如何解释结果。这些例子都给了数据，您可以直接在Stata中使用，甚至扩展您的分析。我们给您快速启动每一个功能，展示一些较常用用途。想要了解更多细节，我们的方法和公式部分提供了计算的细节，我们参考部分会给出更多信息。
Stata是一个很大的软件包，包含了非常多的文档，**过27卷14,000页的内容。不用担心，在Help菜单中输入要搜索的内容，Stata会搜索到关键词、指数，甚至用户编写的程序包，这些会让您得到想要了解的一切。Stata包含了所有这些您想要的内容。
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