Signal Plotter

The Signal Plotter is a Javascript web application. It allows you to write a javascript program: normally a function which accepts a value: "t" time, and returns the amplitude at that value of "t". The simplest usage is to call plot.full(f) where f is the time domain function you have written.

Click the link above: "Signal Plotter" for a simple demo. "Sigplot Demo" takes you to a page with more complex demos.

Buttons

Holding the mouse above any of the buttons gives context sensitive help

The most important buttons are: "plot" which executes your program in the code window, and plots it: normally in the time & frequency domain. And "f(t)" which opens the code window and allows you to edit it, or closes it to save space. After changing the state of the code window you will want to click "fit" or "fill" to optimise screen space usage

A comma separated list of variables can be declared in the "var" window. Each variable gets its own tab and can be accessed as an attribute of the variable $user. The sampling variables are available as $sam, and size through $size.

Once any variable or the contents of the code window are modified the "book" button will highlight. If "book" is clicked the URL will be modified so it reflects the changes. This URL can be bookmarked or saved as a link exactly reflecting the current program and variables

If there is an error in your program in the code window, subtract 4 from the line number. Sorry!

Global Variables

All methods and constants in the Math module are global variables to the code window e.g. PI, E, sqrt, sin

The "plot" object is a global variable with its method "full" which takes a function, and plots its time & frequency domain

The "dsp" object contains FFT functions, and low pass filers