DSP First in Python

DSP demos from http://dspfirst.gatech.edu ported to Python, using Claude Code.

Original MATLAB version by Prof. James H. McClellan, Dr. Jordan Rosenthal, et al. (Georgia Tech, 1994–2021).

Demos

Install PyQt6 and dependencies first.

pip install PyQt6 numpy scipy matplotlib

Sinusoids Drill

Tests the user's ability to identify the amplitude, frequency, and phase of a displayed cosine wave: $x(t) = A\cos(2\pi f t + \phi)$

$ ./sindrill.py

Matlab	Python

Phasor Race

$ ./phrace.py

Matlab	Python

ZDrill

Timed quiz on phasor / complex-number operations.

$ ./zdrill.py

Matlab	Python

Fourier series demo

Illustrates how a periodic signal is built up from its Fourier series.

$ ./fseriesdemo.py

Matlab	Python

Complex Spin demo

$ ./cspin.py

Matlab	Python

Continuous-Discrete Sampling Demo

$ ./con2dis.py

Matlab	Python

Strobe Demo — Rotating Disc / Aliasing Demo

Simulates a rotating disc with an arrow being flashed by a strobe light. Vary the flash rate to observe aliasing concepts.

$ ./strobedemo.py

Matlab	Python

Discrete Convolution demo

$ ./dconvdemo.py

Matlab	Python

Continuous Convolution demo

Visualises continuous-time convolution interactively: y(t) = ∫ x(τ) h(t−τ) dτ

$ ./cconvdemo.py

Matlab	Python

Discrete LTI System demo

$ ./dltidemo.py

Matlab	Python

Continuous LTI System demo

$ ./cltidemo.py

Matlab	Python

Filter Design demo

$ ./filterdesign.py

Matlab	Python

Pole-Zero demo (z-domain / Discrete-Time)

Interactive placement and dragging of poles (×) and zeros (○) in the z-plane. Magnitude/phase frequency response and impulse response update in real time.

$ ./pezdemo.py

Matlab	Python

Spectrogram demo

Demonstrates how window type, window size, FFT size, and overlap affect the spectrogram of linear chirps, sinusoids, or audio files.

$ ./specgramdemo.py

Matlab	Python

DSP First book series

James H. McClellan, Ronald W. Schafer, and Mark A. Yoder wrote three books together, the first 6 chapters are almost the same, as well as two chapters on $z$-Transforms and IIR Filters.

• DSP First: A Multimedia Approach (523 pp.) was published in 1998, focused almost entirely on the digital domain.
• Signal Processing First (512 pp.), published in 2003, expanded the original book, adding several chapters covering Continuous-Time Linear Time-Invariant (LTI) systems, the Continuous-Time Fourier Transform (CTFT), and analog filtering/modulation/sampling. It was designed to serve as a complete, single-semester course covering both analog and digital concepts.
• DSP First, second edition (592 pp.) features three new chapters on Discrete-Time Fourier Transform, The Discrete Fourier Transform, and the Fourier Series.

Chapters	DSP First: A Multimedia Approach (1st Ed, 1998)	Signal Processing First (2003)	DSP First (2nd Ed, 2016)
Introduction	Chap. 1	Chap. 1	Chap. 1
Sinusoids	Chap. 2	Chap. 2	Chap. 2
Spectrum Representation	Chap. 3	Chap. 3	Chap. 3
Sampling & Aliasing	Chap. 4	Chap. 4	Chap. 4
FIR Filters	Chap. 5	Chap. 5	Chap. 5
Frequency Response of FIR Filters	Chap. 6	Chap. 6	Chap. 6
Discrete-Time Fourier Transform			Chap. 7
Discrete Fourier Transform			Chap. 8
$z$-Transforms	Chap. 7	Chap. 7	Chap. 9
IIR Filters	Chap. 8	Chap. 8	Chap. 10
Continuous-Time Signals and LTI Systems		Chap. 9
Frequency Response		Chap. 10
Continuous-Time Fourier Transform		Chap. 11
Filtering, Modulation, and Sampling		Chap. 12
Computing the Spectrum		Chap. 13
Spectrum Analysis	Chap. 9
Complex Numbers	Appx. A	Appx. A	Appx. A
Programming in Matlab	Appx. B	Appx. B	Appx. B
Laboratory Projects	Appx. C	Appx. C	Labs online
CD-ROM Demos	Appx. D	Appx. D	Demos online
Fourier Series			Appx. C

Other books by the authors

• James H. McClellan, known for Parks-McClellan FIR filter design algorithm.

  

  Computer-Based Exercises for Signal Processing Using MATLAB 5, written by James H. McClellan, C. Sidney Burrus, Alan V. Oppenheim, Thomas W. Parks, Ronald W. Schafer, and Hans W. Schuessler, 1994.

• Ronald W. Schafer co-authored two DSP books with Alan V. Oppenheim, Digital Signal Processing (1975) and Discrete-Time Signal Processing (1^st ed. 1989, 2^nd ed. 1999, 3^rd ed. 2009). Co-authored Digital Processing of Speech Signals with Lawrence R. Rabiner, published in 1978.

  

• Mark A. Yoder wrote BeagleBone Cookbook, built campanion website for Discrete-Time Signal Processing 3e, and maintains Signal Processing First website.