Modeling clones evolution in open source systems through chaos theory

A code clone is a code fragment that is identical or similar to another according to a certain similarity definition. Usually, it is a result of certain programmer´s practices. Unjustified cloned codes can cause an increase in maintenance effort. In addition, they are -sometimes-a sign of poor design. This paper presents an approach for modeling clones evolution in open source systems. It adapts chaos theory for predicting clones in new versions of a software system. The number of clones in each version is identified and analyzed as a time series data. The existence of chaos is tested through the calculation of Lyapunov exponent and correlation dimension. Experimental results show that clones evolution in open source systems is a chaotic process. Thus, prediction in new versions can be done with high prediction accuracy using chaos theory.