SADI: sequence analysis tools for stata

SADI is a suite of Stata tools for sequence analysis, with a particular focus on holistic comparisons of sequences using measures such as optimal matching distance. It provides a number of distance measures, including • Optimal matching distance • Hamming distance • Dynamic Hamming distance • Elzinga’s combinatorial X/t measure and • TWED, a time-warping distance measure. It provides a number of utilities for graphing sequence-related data, for summarising sequences, and for handling sequences in general. The main alternatives to SADI are the Stata SQ package (Brzinsky-Fay, Kohler&Luniak, 2006), and the R package TraMineR (Gabadinho, Ritschard, Studer & Müller, 2009). SADI provides some tools that are not in SQ, and is much faster for some important functions. TraMineR is pretty attractive for those working in R, but SADI makes it possible to do a lot in a Stata environment, and has distance measures that are not in TraMineR. Since some of the distance measures are relatively intensive to calculate, they are implemented as C plugins, rather than pure Stata or Mata code. This means that they are available only for Windows and Linux, 32- and 64-bit. If you would like to compile them for another platform, please contact Brendan Halpin, brendan.halpin@ul.ie, or see section 5. This document summarises the functionality offered by SADI, with worked examples, and reproduces the help files (see section 6). Many of the measures in SADI are discussed in detail in Halpin (2014) and Halpin (2012).