Light Bulb Filament: What Equations Describe Its Shape?

[schulzy]

Homework Statement

I want to modelling a light bulb filament in MATLAB, but I don't know, what functions describe this shape. My question is, what are equation (x,y,z) which describe the light bulb filament.

 

[R.Harmon]

If you just mean a spiral shape then something like (x,y,z)=(Sin(t),Cos(t),t) should work using a parametric plot (in mathematica anyway, I don't use matlab).

 

[schulzy]

I know that
x=cos(t)
y=sin(t)
z=b*t
these equation describe a simple spiral, but I want to drawing complicated shape, like in attachment.