Introduction In my current job, I study HIV at the genetic and biochemical levels. Thus, I often work with data involving the sequences of nucleotides or amino acids of various patient samples of HIV, and this type of work involves a lot of manipulating text. (Strictly speaking, I analyze sequences of nucleotides from DNA that are reverse-transcribed from […]
Introduction A graduate student in statistics recently asked me for advice on how to find a job in our industry. I’m happy to share my advice about this, and I hope that my advice can help you to find a satisfying job and develop an enjoyable career. My perspectives would be most useful to students […]
As I go about cleaning and merging data sets with R I often end up creating and using simple functions over and over. When this happens, I stick them in the DataCombine package. This makes it easier for me to remember how to do an operation and others ...
I often want to quickly create a lag or lead variable in an R data frame. Sometimes I also want to create the lag or lead variable for different groups in a data frame, for example, if I want to lag GDP for each country in a data frame. I've found ...
Update (10 March 2013): FillIn is now part of the budding DataCombine package. Sometimes I want to use R to fill in values that are missing in one data frame with values from another. For example, I have data from the World Bank on government deficits...
We demonstrate a comparison among various implementations of Rolling Regression in SAS and show that the fastest implementation is over 3200X faster than traditional BY-processing approach.More often than not, we encounter a problem where an OLS over a...
Demo SAS implementation of Regularized (Linear) Discriminate Analysis of J. Friedman (1989)[1]. Simpler introduction can be found at [2]. Regularized QDA follows similarly.To save coding, I called R within SAS to finish the computation. For details to ...
In Chapter 2 of the book "Bayesian Computation with R" by Jim Albert, the philosoph of Bayesian statistics is introduced using an example where a parameter regarding proportion of heavy sleeping college students, i.e. those have more than 8 hours sleep...
The book "Bayesian Computation with R" by Jim Albert is an easy to read entry level book on applied Bayesian Statistics. While the book was written for R users, it is not difficult to translate the languages between R and SAS and I believe it is a good...
One guy asked in a SAS forum about a typical table look up problem: He has a data with two IDs: id1 id2 a b a e b c b e c e d e and he wants to generate a new data set with the following structure according to above information : id a b c ...
