sqrt (-1)

[Unregistered]

I've recently took up an intrest in fractals. Now I would like to write a program so I can draw one, specifically the mandelbrot set. My problem is i don't know how to use imaginary numbers in C, i'm using Bordland C++ 3.0 but also have DJGPP. The equation for drawing the mandlebrot set is f(n) = f(n)^2 + C. Now my constant C = 1 + i and my first point, f(n), is 2+i.
So f(n) = (2+i)^2 + 1 + i. I can do this out by hand, I get
4 + 4i + i^2 + 1 + i which simplfies to 4 + 5i. I use that in my next iteration. I need to find out how to use imaginary numbers in C or where I can get a library so I can use them. Thanks for any help.

[Salem]

Start with

typedef struct {
    double real;
    double imaginary;
} complex_t;

Then write a few functions to add / multiply / sqrt

[Unregistered]

I'm not the most advanced C programmer, could you give me an example on how to write a function where you preform a math function, doesn't matter which one really. Thanks For Any Help.

[Salem]

http://www.google.com/search?q=mande...et+source+code

// from http://mathworld.wolfram.com/ComplexMultiplication.html
complex_t c_mult ( complex_t a, complex_t b ) {
    complex_t result;
    result.real      = a.real * b.real - a.imaginary * b.imaginary;
    result.imaginary = a.real * b.imaginary + a.imaginary * b.real;
    return result;
}