In my recent series on testing I concentrated on dynamic testing, i.e. executing some or all of your code to see if it works. The other type of testing is static testing. This was featured briefly in my “SAS Software Development With The V-Model” paper…
NOTE: Programming Languages Can Be Copied…
… so says Yves Bot, advocate general at the Court of Justice of the European Union (CJEU). Mr Bot’s guidance was issued in response to the July 2010 High Court case between SAS and World Programming Limited (WPL). The CJEU still needs to make a full …
How many days until?
A simple little macro I whipped up that’ll count down the number of days until an important event. %macro daysUntil(event, date); data _null_; diff = datdif(today(), input(“&date.”, anydtdte10.), ‘act/act’); call symput(‘days_until’, strip(diff)); run; %put There are &days_until days until &event; %mend; Macro call is straight forward: %daysUntil(Christmas, 12/25/2011); %daysUntil(Columbia_Marathon, 03/10/2012); I could have used various […]
Too many pies can be hard to digest
On his SAS and R blog, Ken K. recently posted an example of a visualization technique called “small multiples”. In this exercise, Ken shows the programming technique for replicating a particular series of pie charts in R as well as in SAS. It’s a useful exercise to learn from, but […]
10 toughest interview questions for R developers (1)
I recently discovered 10 questions most daunting in R development, and I am trying to find the answers below.
1. Data structure — How many data structures R has? How do you build a binary search tree in R?
2. Sorting — How many sorting algorithms…
Those most productive R developers
The number of R packages on CRAN is 3,483 on 2011-12-12. The growth of R package in the past years can be fitted by a quadratic regression perfectly.
I am always interested in who are maintaining those packages. Then I wrote an R script to extract …