April, 2010
hash-2.0.0
Posted by Christopher Brown in Blog, R on April 30, 2010
The hash-2.0.0 package has been uploaded to CRAN. This version was developed in conjunction with R-2.11.0 and was refactored for performance. hash-2.0.0 requires R-2.10.0 or later and will not be supported on earlier versions of R. This is a result of recent changes to the language itself.
R : NA vs. NULL
Posted by Christopher Brown in Blog, R on April 25, 2010
It is common for programming languages to have a NULL value. What often leads to confusion is the fact NULL can have two distinct meanings. In the first, NULL is used to represent missing or undefined values. This is well appreciated in SQL. In the second case, NULL is the logical representation a statement that is neither TRUE nor FALSE. This indeterminacy is the basis for ternary logic. While these meanings are distinct, they are very often related. When missing values (the first meaning) are evaluated, the desired result is often an ambiguous result (the second). That is, the former implies the latter. In programming, the distinction is often unnecessary and glossed over and the concepts become confounded.
Augustus 4.1.1 Available
April 2010
Open Data Group’s open source scoring engine has been updated with additional functions and features. It is also compliant with the most recent PMML standard.
Augustus is a PMML 4-compliant scoring engine that works with segmented models. Augustus is designed for use with statistical and data mining models. The new release provides Baseline, Tree and Naive-Bayes producers and consumers. Read the rest of this entry »