3-dimensional parametric equations [Updated] Look lower for update.... 1. The problem statement, all variables and given/known data Well, my problem is that I need to give some examples on 3-dimensional parametric equations. So far I've found out what parametric equations are, and more specifically what 3-dimensional parametric equations are. But now I am being asked to give some real-world examples of these. 2. Relevant equations A 3-dimensional parametric equations is an equation of something in a 3d-coordinate system, where each coordinate x,y,z are expressed by the same parameter t: x(t) = f1(t) ^ y(t) = f2(t) ^ z(t) = f3(t) 3. The attempt at a solution Well, so far I've found out that Solar Winds, Aurorae and the movement of the plasma inside a Tokamak are all 3-dimensional parametric equations. My problem is that while I know that the movements can be expressed by 3-dimensional parametric equations, I have absolutely no idea how these equations look like. I've searched all around the Internet, but I can't find any equations for this - or anything at all that looks like it. I hope you can help. Thanks in advance. Update: I have now advanced a bit, and acutally found a simulation of the particles moving inside a tokamak, which shows that the particles drift up or down depending on their charge q. So now I have a new problem: 1. The problem statement, all variables and given/known data My problem is now that I do understand the mathematics / physic equations used in the simulations. The simulations starts with introducing all the varibles and functions: Code (Text): B0:=1 v,m:=1,.01 x,y,z:=3,0,0 vx,vy,vz:=v,v*q,0 t,dt:=0,.01 Integratemethod:=RK4 func det(a,b,c,d) return a*d - b*c endfunc func R(x,y) return (x^2+y^2) endfunc func acc(va,vb,ba,bb) return (va*bb-vb*ba)/m endfunc func Bx(x,y,z) return y*B0/R(x,y) endfunc func By(x,y,z) return -x*B0/R(x,y) endfunc func Bz(x,y,z) return 0 endfunc Model tokamak x':=vx y':=vy z':=vz vx':=q*det(vy,vz,By(x,y,z),Bz(x,y,z))/m vy':=q*det(vz,vx,Bz(x,y,z),Bx(x,y,z))/m vz':=q*det(vx,vy,Bx(x,y,z),By(x,y,z))/m endmodel After this, it makes a loop which constantly calculates the integrated function of "tokamak" (why this?). And after this adding the timedifference dt to the time variable t: Loop: Code (Text): integrate tokamak(t,dt) t:=t+dt 2. Relevant equations I can see the that function det, is finding the determinant, though I do not know why this is relevant. All of it is something with vectors, but I am not sure how. 3. The attempt at a solution Tried looking at it so long, but I am not good enough at vectors and integration yet, so I simply cannot see excacly what is going on. I really hope that one of you can open my eyes. Thanks in advance.