Which formulas describe the magnetic field/field lines?

[ahxbshe1]

hello!
im not very familiar with electromagnetic fields and classical physics, so i turn to you for help,
a problem:
assume you have a magnetic dipole in center (0,0) of a xy plane,
i want to plot the vector of the field at an arbitary point on this plane,and to plot the filedlines, how do i do this? which formulas describe the magnetic field/fieldlines?
thankyou verymuch
ahxbshe

 

[berkeman]

hello!
im not very familiar with electromagnetic fields and classical physics, so i turn to you for help,
a problem:
assume you have a magnetic dipole in center (0,0) of a xy plane,
i want to plot the vector of the field at an arbitary point on this plane,and to plot the filedlines, how do i do this? which formulas describe the magnetic field/fieldlines?
thankyou verymuch
ahxbshe

Welcome to the PF. This web page has a reasonable introduction to magnetic field. Does it help?

http://en.wikipedia.org/wiki/Magnetic_field

.