KeepNotes blog

This post is to talk about how to compare two paired areas under ROC curves(AUC) for diagnostic accuracy by non-inferiority test.

Reference: Tests of equivalence and non-inferiority for diagnostic accuracy based on the paired areas under ROC curves

If you often work with data manipulation, obviously you need to know how to merge and transpose data as that is very common in our data processing.

Selecting N rows from a dataset or K-th element from a macro variable is a common data manipulation process. This post is listing the ways how to resolve these questions.

Handling the duplicates and missing values in data manipulation is a very common process. This post is taking a few examples to list how to accomplish it from a datasets in SAS.

This post is talking about how to display descriptive statistics for variables quickly. In the sense that we would like to know an usual and agile way to accomplish it in SAS.

Sometimes we would want to list column names of a SAS dataset, which can be useful in other programs, such as proc freq, proc transpose.

Standing up a flag here, I'm planning to keep a series of notes to minute my questions met in sas learning. Practice is the best teacher, practice makes perfect!

由于Hexo博客中的about页面默认是通过markdown渲染的，假如想用自定义的页面，比如HTML/CSS方式，那么该如何实现呢？

对团队R包开发的协作经验，做个小结；并为个人开发R包做个基础知识准备

Assume that you input a character string 20211109 with a sas format like yymmdd8. that specifies how sas must interpret the character string, you will get a numeric number 22593.

This is reference to the "Chapter 8 A graphical compendium" in <SAS and R: Data Management, Statistical Analysis, and Graphics (second edition)>.

I believe that the capability of data science is more than just building predictive models, data visualization is also an integral part, especially in a convincing way.

This is reference to the "Chapter 3 Statistical and mathematical functions", "Chapter 4 Programming and operating system interface" and "Chapter 5 Common statistical procedures" in <SAS and R: Data Management, Statistical Analysis, and Graphics (second edition)>.

This is reference to the 2.3 section of Data management and 2.4 Date and time variables in <SAS and R: Data Management, Statistical Analysis, and Graphics (second edition)>.

在R中常说的数据集操作是指处理数据框类型的数据，当然有时也会是其他的数据类型。在SAS中就是数据集，SAS相比其他编程方法来说数据类型还是太少了。。

处理数据，常见的不外乎combination, collation, and subsetting

This is reference to the 2.1 to 2.2 section of Data management in <SAS and R: Data Management, Statistical Analysis, and Graphics (second edition)>.

我一直想找一个合适的方法来记录SAS的学习笔记，最好能结合以往的编程经验（如R or Python）；我想到了当初学习Python的时候是根据实际需要，结合R/Perl的既往经验来互补学习，那么SAS也是可以这样。

What is Git?

Git is a version control system used to track changes in computer files. Git's primary purpose is to manage any changes made in one or more projects over a given period of time. It helps coordinate work among members of a project team and tracks progress over time. Git also helps both programming professionals and non-technical users by monitoring their project files.

What is Gitlab?

GitLab is a web-based Git repository that provides free open and private repositories, issue-following capabilities, and wikis. It is a complete DevOps platform that enables professionals to perform all the tasks in a project—from project planning and source code management to monitoring and security. Furthermore, it allows teams to collaborate and build better software.

以下是我在shiny publish中遇到的问题以及解决方法，以供大家参考

This post is the reading notes for the e-book “SAS Programming in the Pharmaceutical Industry” to keep recording some knowledge points about pharma programming.

I have a strong interest in data visualization. For me, the purpose to learn this skill is driven by having a good understanding and examination for the question one wants to solve.

It is not to be denied that sas is an essential skill for statistical programmers in the pharma field. Of course sas is a programming language which can be derived to different using requirements in different fields. So I think we should follow the actual requirements in the pharmaceutical industry to learn SAS if you want to be a qualified statistical programmer. Therefore the purpose of this post is to record some actual applications by sas so that I can understand and remember sas syntax clearly.