iSAX – The Implementation

Before continuing with this chapter and starting to write code, make sure that you have a good understanding of the information covered in the previous chapter because this chapter is all about implementing iSAX in Python. As a general principle, if you cannot perform a task manually, you are not going to be able to perform it with the help of a computer – the same principle applies to constructing and using an iSAX index.

While reading this chapter, keep in mind that we are creating an iSAX index that fits in memory and does not use any external files to store the subsequences of each terminal node. The original iSAX paper suggested the use of external files to store the subsequences of each terminal node mainly because back then, RAM was limited compared to what is the case today, where we can easily have computers with many CPU cores and more than 64 GB of RAM. As a result, the use of RAM makes the entire process much faster than if we...