Book Image

Time Series Indexing

By : Mihalis Tsoukalos
Book Image

Time Series Indexing

By: Mihalis Tsoukalos

Overview of this book

Time series are everywhere, ranging from financial data and system metrics to weather stations and medical records. Being able to access, search, and compare time series data quickly is essential, and this comprehensive guide enables you to do just that by helping you explore SAX representation and the most effective time series index, iSAX. The book begins by teaching you about the implementation of SAX representation in Python as well as the iSAX index, along with the required theory sourced from academic research papers. The chapters are filled with figures and plots to help you follow the presented topics and understand key concepts easily. But what makes this book really great is that it contains the right amount of knowledge about time series indexing using the right amount of theory and practice so that you can work with time series and develop time series indexes successfully. Additionally, the presented code can be easily ported to any other modern programming language, such as Swift, Java, C, C++, Ruby, Kotlin, Go, Rust, and JavaScript. By the end of this book, you'll have learned how to harness the power of iSAX and SAX representation to efficiently index and analyze time series data and will be equipped to develop your own time series indexes and effectively work with time series data.
Table of Contents (11 chapters)

Visualizing iSAX as a Collapsible Tree

Although the zoomable icicle looks very promising, some people might want a visualization that looks like a tree but still has some of the versatility of the zoomable icicle. For those people, we are going to try the Collapsible Tree.

First, we go to the CollapsibleTree directory and then we run the Python web server. Then, we go to http://localhost:8000/. Figure 6.13 shows the output of the Collapsible Tree visualization:

Figure 6.13 – Visualizing iSAX as a Collapsible Tree

Figure 6.13 – Visualizing iSAX as a Collapsible Tree

The main advantage of the Collapsible Tree is that we can expand or collapse nodes at will, which means that we can easily concentrate on the nodes that interest us the most instead of getting lost in the details of the iSAX index.

However, the Collapsible Tree does not display the number of subsequences stored under each subtree of the index.

In this last section, we saw the operation of the Collapsible Tree and understood its...