pltSig version 14Sep23

Copyright © 2023, Paul Mennen
The pltSig Matlab toolbox is derived from an earlier toolbox called plt which is an alternative plotting interface to Matlab's native plot and plotyy routines. This alternative plotting interface is still the foundation of the toolbox but I changed the name to pltSig because the main focus of the toolbox has shifted from the plotting interface to the applications that depend on it. (Sometimes I still call the toolbox plt for conciseness as well as habit.)

The pltSig applications:
            with practical or educational value in various topics of signal processing, math, & engineering

    ▪ afilt.m
    ▪ airspeed.m  
    ▪ carlo.m
    ▪ circles12.m
    ▪ curves.m
    ▪ editz.m
    ▪ erip.m
    ▪ fseries.m
    ▪ gauss.m
classical analog filter design
aircraft performance modeling
Monte Carlo simulation
geometrical puzzle
classic plane curves
z-plane analysis
equal ripple digital filter design
synthesis of harmonic functions
summation of random variables  
▪ gpsLog.m
▪ julia.m
▪ hermite.m
▪ motion.m
▪ pltmap.m
▪ psdZoom.m  
▪ weight.m
▪ wfall.m
▪ winplt.m
GPS data analysis & simulation
Mandelbrot & Julia set fractals
Hermite polynomial interpolation
Brownian motion simulation
2D cubic interpolation & convolution
power spectral averaging & zoom
classic sound level weighting curves  
clipping distortion effects
FFT windowing

These applications include capabilities and features not found elsewhere on the file exchange, and most of them merit an individual file exchange submission. However, I chose to combine them into a single toolbox because my goals go beyond the individual applications - primarily to promote a particular graphical interface style that makes applications easier to use. Some aspects of this style include:

The pltSig utilities:

If you write Matlab programs, you will almost certainly find one or more of the included utilities useful. Most, but not all, are focused on the problems of GUI programming. Some of the more notable utilities are described below:

plt An alternative to the native Matlab plot and plotyy routines. A common complaint programmers have about plot (and even more so with plotyy) is that to do anything beyond the mundane one needs to use obscure handle graphics commands that are only easy to find if you are already familiar with them. plt solves this problem by clearly explaining every option and parameter in one place, giving many examples of the use of every important parameter. There are also many other advantages to plt, to numerous to mention here. Features are added to plt regularly based on suggestions from users.
prin This is what sprintf would have looked like if it was first written for Matlab instead of for the c library.
figpos It is often difficult to size and position a figure window in a way that is ideal for all computers because of the wide disparities of screen resolutions and aspect ratios as well as different taskbar sizes and locations. These problems become even more difficult for applications requiring more than one figure window. The figpos routine makes solving such problems trivial, or at the very least, more manageable.
pltwater & pltImage These routines allow you to easily create 3D waterfall and intensity plots, and like plt, they include many well-documented options.
colorpick Creates a color palette that allows you to easily choose the color that you find most satisfying for a particular trace or screen element. Usually, if you are even given such a choice, you will be presented with a single palette including all possible color choices. The problem with that is that the color you want will occupy a microscopic portion of the palette, making the choice a frustrating trial-and-error process. colorpick is different because you can adjust the palette to focus on the range of colors that interest you. A large rectangle filled with the candidate color choice eliminates most of the trial-and-error repetition.
pp A vector pretty printer which overcomes several of the annoyances of the Matlab disp function.


I'm interested in hearing about your problems and suggestions relating to this toolbox.
You can reach me at
I hope using pltSig enhances your Matlab experience
and increases your knowledge about signal processing.