I'm a R-lover and believe that anything SAS can do, R can do better. As R is such a powerful language for statistical analysis in clinical trials. Once, I posted an article that said how to insert blank rows, so I looked up how to do that in R.
R - Replace NA with Zero and Empty String in Multiple Columns
This casual note is to record how to use R to replace the NA with 0 or any string. Generally, NA can be generated for different reasons, like unclean data, data transformation, or missing values. Otherwise, we have to convert NA to zero or other stings in order to present them in tables or listings.
Boxplot With Jittered Points in R
The box plot is used to demonstrate the data distribution in common and to look for outliers. We can also see where the 25% and 75% quarters are, as well as the median value from the box. As a result, it's a very helpful visual chart.
How to save graphs in SAS
Recently, I'm a little confused how to create or save PNG graphs in SAS. Normally, we would have been to create RTF or PDF instead but there was sometimes a specific requestment to save as PNG directly. So we need to know how to complete it in SAS when I have a graph generated by SGPLOT or GTL procedure.
Definition of least-squares means (LS means)
This article aims to learn the basic calculation process of least-squares means (LS means).
Conduct an ANCOVA model in R for Drug Trial
This article is to illustate how to conduct an (Analysis of Covariance) ANCOVA model to determine whether or not the change from baseline glucose is affected by treatment significantly. In other words, using ANCOVA to compare the adjusted means of two or more independent groups while acounting for one or more covariates.
Capturing statistic tables from SAS procedure - SASlearner
As a new SAS user, a common question that is always asked and searched on google is: how can I get the statistic into a table?
Combine RTF files into one file
This post is just a note referred from one article as shown below that I think would be beneficial for anyone who is as new as I am, as this requirement is fairly common in pharamaceutical programming.
Post-hoc and ad-hoc of statistical analysis in clinical trials
一些过往学习的记录,均是参考和摘抄了一些网上的资料,无法保证描述的准确性。。。
http://onbiostatistics.blogspot.com/2009/01/data-dredging-vs-data-mining-post-hoc.html
SAS 数据集操作
Symbols count in article: 2.4k Reading time ≈ 2 mins.
How to insert blank rows - SASlearner
If you'd like to add one blank row in your report, as shown below:
Example of SDTM and ADaM datasets from the CDISC
Here is to present a set of SDTM and ADaM datasets from CDISC pilot projects as resources for R develpment and programming.
File and Directory Manipulation - SAS&R
In this article, we are going to present how to work with files and folders in R and SAS.
Bland-Altman Analysis
The Bland-Altman analysis is the most common method of assessing the agreement in method comparison in IVD CT or CE trials.
Non-Inferiority Test for Paired ROC Curves
This post is to talk about how to compare two paired areas under ROC curves(AUC) for diagnostic accuracy by non-inferiority test.
Merge and Transpose - SASlearner
Symbols count in article: 3.5k Reading time ≈ 3 mins.
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.
Select N Rows or K-th Elements from Macro Variable - SASlearner
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 Duplicates and Missing values - SASlearner
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.
Displaying Descriptive Statistics for Variables - SASlearner
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.
Listing Column Names in SAS - SASlearner
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
.