This year I have the chance to review the book NumPy Cookbook written by Ivan Idris and published by Packt Publishing. It introduces the numpy library by examples (which the author refers as recipes :). It is written with a simple language and it covers a wide range of topics, from the istallation of numpy to the combination with Cython.
My impression of the book was good and, in particular, I liked the structure of the book. Every chapter face a series of problem related to the a specific topic through examples. Each example comes with an introduction to the problem that will be solved, the code commented line by line and a short recap of the techniques applied to solve the problem. Most of the examples are about practical problems and the code is made to be adapted in your own projects.
Chapters 5 and 10 are my favorite. The first one is about audio end image processing and explains some basic operation about the manipulation, the generation and the filtering of audio and video signals. The second is about the combination of numpy with some scikits,like scikits-learn, scikits-statsmodels and pandas. I loved these chapters because they cover some topics related to complex fields, such as machine learning and data analysis, in a very straightforward fashion.
Some examples presented by the book kept my attention. In particular, I found very interesting the one about the generation of the Mandelbrot. This example contains an explanation of the mathematical formula behind the fractal and the combination of the image generated using the formula and a simpler one. It is my favorite because provides one of the most practical explanation of the Mandelbrot fractal I have ever seen.
This book could be a good starting point for who want to begin with numpy using a gentle approach. It can be used also as a manual which can help you in the development of small parts of more complex projects.