This code creates a decision tree model in R using party::ctree() and prepares the model for export it from R to Base SAS, so SAS can score new records. SAS Enterprise Miner and PMML are not required, and Base SAS … Continue reading →
Blog Archives
Model decision tree in R, score in Base SAS
Paired sample t-test in R
Let’s walk through using R and Student’s t-test to compare paired sample data. The book Statistics: The Exploration & Analysis of Data (6th edition, p505) presents the longitudinal study “Bone mass is recovered from lactation to postweaning in adolescent mothers … Continue reading →
Basic line chart with ggplot2
ggplot2 is a package for R which easily draws plots that are easier on the eyes than R’s built-in plotting functions, though the grammar is different than what is commonly used in R. This code demonstrates how to prepare a … Continue reading →
Two browsers for R help documentation
The same excellent documentation for R commands is available through two different help browsers: text and HTML, and let’s see how how each looks, works, and how to switch the default. Look and feel Here is how both look for … Continue reading →
Benchmarking R, Revolution R, and HyperThreading for data mining
Usually data mining benchmarks measure lift, precision, etc., but wasting analyst time hurts the ROI of any project. I recently upgraded my notebook (where I often use R for data mining) and was faced with two questions: for the fastest … Continue reading →
Text Data Mining with Twitter and R
Twitter is a favorite source of text data for analysis: it’s popular (there is a huge volume of variety on all topics) and easily accessible using Twitter’s free, open APIs which are easily consumable in JSON and ATOM formats. Some … Continue reading →
Compcache on Ubuntu on Amazon EC2
The following fully-automatic Bash script downloads, compiles, and initializes compcache version 0.6.2 on Ubuntu Karmic Koala (9.10). This script creates two swaps with a maximum of 4GB uncompressed size each. Two swaps are used to take advantage of 2 CPUs (or CPU cores in a multicore CPU). Compcache is a fascinating memory compression system. The 
Validating credit card numbers in SAS
Major credit card issuing networks (including Visa, MasterCard, Discover, and American Express) allow simple credit card number validation using the Luhn Algorithm (also called the “modulus 10″ or “mod 10″ algorithm). The following code demonstrates an implementation in SAS. The code also validates the credit card number by length and by checking against a short 
Weighting model fit with ctree in party
Conditional inference trees (ctree) in package party allows weighting which is useful when one classification outcome is more important than another. Useful examples are not difficult to imagine: in a marketing direct mailing, a false positive (non-res...
Setting the HTML title tag in SAS ODS (the right way)
In our department and various places on the Intertubes, SAS programmers set the HTML title tag (which sets the title in web browsers and on search engines) in ODS using the headtext option: ods html headtext="<title>My great report</title>" /* wrong! */ file="foo.html"; This may work in some situations, but it’s ugly and wrong. To see 
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
