Raw metrics for measuring software evolution in open source software systems

The evolution of a software system can be studied in terms of how various properties as reflected by software metrics change over time. We build a release history model by analysing the compiled class files. Our release history model captures metadata and 58 different metrics at a class level. We also build a class dependency graph for each release in the evolution history. The data selection and metric extraction method that we use ensures that we study non-trivial software allowing us to extend our findings to other comparable software systems built in Java. The metrics for each software system are in a separate data file. The raw metric data files (50 .txt files in a .zip file measuring ~58MB in total) contain the following columns: (1) Fully Qualified Class Name; (2) Metric Name (We use the abbreviations as defined in Chapter 4); (3) a list of metric values for each release of the software. Columns with empty values indicate that the class did not exist in that release.