ThinkDSP

ThinkDSP#

Think DSP is an introduction to Digital Signal Processing in Python.

Note: This is the second edition of Think DSP, which is a work in progress.

Which repository?#

Think DSP has two GitHub homes:

  1. think-dsp library — ThinkDSP: notebooks can download thinkdsp.py; optional pip install think-dsp.

  2. First edition (PDF/HTML) and archived code/ tree — ThinkDSP: HTML, PDF; edition-1 branch.

  3. Second edition draft (this book) — ThinkDSP2: one notebook per chapter with text, code, and exercises.

  4. Notebook styles:

    • Separate code and exercises — ThinkDSP nb/ (chap01.ipynb / chap01soln.ipynb, …).

    • Full chapter notebooks — ThinkDSP2 notebooks/ (no solutions) or soln/ (with solutions).

The premise of this book (and the other books in the Think X series) is that if you know how to program, you can use that skill to learn other things. I am writing this book because I think the conventional approach to digital signal processing is backward: most books (and the classes that use them) present the material bottom-up, starting with mathematical abstractions like phasors.

With a programming-based approach, I can go top-down, which means I can present the most important ideas right away. By the end of the first chapter, you can decompose a sound into its harmonics, modify the harmonics, and generate new sounds.

Think DSP is a Free Book. It is available under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International, which means that you are free to copy, distribute, and modify it, as long as you attribute the work and don’t use it for commercial purposes.

Work in Progress#

In the first edition, the text was in LaTeX and the code was in Python modules. For this edition, I have combined the text, code, exercises, and solutions into Jupyter notebooks.

At this point, I have tested that the code in the notebooks runs, but I have not checked (1) the references from the text to the figures, and (2) cross-references between sections.

I will work on these things gradually, but in the meantime, please let me know if you find problems. The best way to do that is to open an issue.

If you would like to contribute a correction, please note that the source documents are the notebooks in the soln directory. I use a script to generate the notebooks directory. So if you make any changes, please

  1. Make sure you have pulled the most recent notebook from the repository.

  2. Make the minimal change/correction, and

  3. Clear the output cells before you push your notebook and create a pull request.

If you are not comfortable using Git, it is probably better to create an issue and describe the change.

Running the code#

The chapters of this book are in Jupyter notebooks that contain the text, code, and exercises.

To run the notebooks, you have two options:

Option 1: Run the notebooks on Google Colab (easiest, no installation required).

Option 2: Install Python, Jupyter and the required libraries on your computer.

The following sections explain these options in detail.

Option 1: Run on Colab#

Use these links to open the notebooks on Colab. If you want to modify and save any of them, you can use Colab to save a copy in a Google Drive, in your own GitHub repo, or on your computer.

Notebooks with no solutions:

Use these links if you want to work on the exercises.

Notebooks with solutions:

Use these links if you want to see solutions to the exercises.

Option 2: Install on your computer#

See the ThinkDSP2 README for clone and Conda setup. Notebooks download thinkdsp.py by default; pip install think-dsp is optional.

You can also download the repository Zip or notebooks Zip.

Freesound#

Special thanks to Freesound (http://freesound.org), which is the source of many of the sound samples I use in this book, and to the Freesound users who uploaded those sounds. I include some of their wave files in the GitHub repository for this book, using the original file names, so it should be easy to find their sources.

Unfortunately, most Freesound users don’t make their real names available, so I can only thank them using their user names. Samples used in this book were contributed by Freesound users: iluppai, wcfl10, thirsk, docquesting, kleeb, landup, zippi1, themusicalnomad, bcjordan, rockwehrmann, marchascon7, jcveliz. Thank you all!

Here are links to the sources:

http://www.freesound.org/people/iluppai/sounds/100475/

http://www.freesound.org/people/wcfl10/sounds/105977/

http://www.freesound.org/people/Thirsk/sounds/120994/

http://www.freesound.org/people/ciccarelli/sounds/132736/

http://www.freesound.org/people/Kleeb/sounds/180960/

http://www.freesound.org/people/zippi1/sounds/18871/

http://www.freesound.org/people/themusicalnomad/sounds/253887/

http://www.freesound.org/people/bcjordan/sounds/28042/

http://www.freesound.org/people/rockwehrmann/sounds/72475/

http://www.freesound.org/people/marcgascon7/sounds/87778/

http://www.freesound.org/people/jcveliz/sounds/92002/

Contents