Imaginary and complex numbers

[DeMarHc]

Hello,

I am quite new to Flash and Actionscript. I was wondering if there is any way to use imaginary numbers in flash. How would I assign the value of sqrt(-1) to a variable? Also is it possible to perform complex number calculations in Flash?

Thank you.

[georgegowan]

Hey, you can do some pretty complex number calculations in flash...
Im not quite sure what you mean by imaginary numbers but you can assign almost anything to a variable

myVar = Math.sqrt(100);

trace (myVar)

it wont allow you to use -1 as nothing squared can = -1 ;P
Im not sure how new you are so all this means is
myVar = Math.sqrt(100);
this creates a variable called myVar and sets it value to the square root of 100

trace (myVar)
this just tells you what the value of myVar is... kinda like echo or print used in other languages.

[adragons]

In math sqrt(-1) = i. so sqrt(-100) = 10i.

but no, you can't sqrt(-1) just returns NaN (not a number).

I'm not sure of what 'complex' numbers calculations are.

[swak]

He's basically wondering if you can do math with imaginary numbers. Looking through the Math class, (go to the built-in flash help) all of the functions didn't involve an imaginary number. I very much doubt flash can do imaginary calculations. Except for a calculator I don't see what you want it for, care to indulge me?

[DeMarHc]

Thanks to everyone for replying!

I am actually building an application to introduce acoustics to younger children. Thus, I am building a model of a simple trumpet and the calculations used to build the model involves imaginary numbers. None of the built-in functions of Flash supports imaginary numbers.

DeMarHc

[Dickee]

Hey DeMarHc!

I have some information on your query ... checkout my dated-but-still-relevant AS2 Library for the class com.wis math.alg.Complex.as to explore a multitude of complex number methods.

Examples that utilize the application of complex numbers:

Complex Number Calculator
Cubic Polynomial Equation - Cardan
Quartic Polynomial Equation - Cardan

Lifaros created an example tool to explore the various wave transforms Fourier Wave Generator

Fourier Transform ... my class com/wis/math/calc/Fourier.as is a port of Paul Bourke's C implementation for discrete (dft) and fast (fft & fft2d) Fourier transforms that support digital signal processing applications. It's a bit hard to follow the code, but it's worth the effort to study these algorithms. They populate their own local complex objects as holders for signal transformation so you are able to follow the progression of the logic ... I plan to eventually refactor the Fourier class to extend the Complex class.

Complex Numbers from wikipedia provides definition and summaries for the application of complex numbers in control theory, signal analysis, improper integrals, quantum mechanics, relativity, applied mathematics, fluid dynamics, and fractals.

Richard

[DeMarHc]

Hi Richard!

Thank you soooo much! You are a life saver! This is going to help me lots! Thank you!!

DeMarHc

[Dickee]

Ooops! I meant to include source links for the 3 examples above, but forgot to edit before posting.

Complex Number Calculator: Source
Cubic Polynomial Equation - Cardan: Source
Quartic Polynomial Equation - Cardan: Source

[Dickee]

Admin: I suggest you extend edit time a bit please.

DeMarHc:

I'll walk you through the 4 step 'i' cycle ... open the calculator:

Press C to clear memory ...
The left field is the real part and the right field is the imaginary part of the complex number input ...
Each cycle's input should be 0 for the real and 1 for the imaginary, which represents the complex object 'i' ...

0. Input/Enter ... = i
1. Input/*/Enter ... i * i = -1
2. Input/*/Enter ... -1 * i = -i
3. Input/*/Enter ... -i * i = 1
4. Input/*/Enter ... 1 * i = i
... ad infinitum