Help on field lines simulation

[lechko]

Hello everyone, I am trying my best to do this simulation on Matlab to show the expancion of Magnetic field lines out of a coil. Now, finding the amplitude and direction of the field at a given place is pretty simple, the trick is to produce those tidy lines we all see in books, i gather they are supposed to be tangential to the field direction but there has to be something that I am missing... why in all of the books they chose to show us those curving lines and when u think of it, it's supposed to be a page filled with arrows.
I really hope this question is not inappropriate here but I am sure there's smtng I'm missing there and can't quite figure what.

thank you
lechko

 

[enigma]

Welcome to the forums, Lechko!

Every point in a field has a magnitude. The pics in the books trim them out for clarity.

If you're doing it in Matlab, you may want to look into the quiver and quiver3 commands. They plot vector fields with magnitude (u(i),v(i),w(i)) at points (x(i),y(i),z(i)) which are fed into the command.

 

[lechko]

so every poit on the same line has the same magnitude and the "quiver" command will just point them out? great!
i already started thinking of some complicated "For"-"If" structure :)
thanks alot!