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Easy Java Simulations (2001- ) => Questions related to EJS => Topic started by: lookang on August 08, 2012, 05:15:48 pm



Title: is there an easier way to draw static magnetic field lines of a bar magnet?
Post by: lookang on August 08, 2012, 05:15:48 pm
dear prof,

is there an easier way to draw static magnetic field lines of a bar magnet?

notice is my source codes the way i made the visible foe B=1, B=2, B=3, B=4?


i cant be doing this way for B=100 for example.

is there a way i can use array 3D trails ?
or is there a analyticCurve3D for array?

thanks!


Title: Re: is there an easier way to draw static magnetic field lines of a bar magnet?
Post by: Fu-Kwun Hwang on August 08, 2012, 05:35:53 pm
I think the way I calculated the field is by using Biot-Savart law.
Calculate magnetic field sue to a coil. The solenoid is simple copy of many coils. So just need to sum up the field from one coil.
You should be able to calculate it.

The magnetic field of a bar is the same as the field of a solenoid.


Title: Re: is there an easier way to draw static magnetic field lines of a bar magnet?
Post by: lookang on August 08, 2012, 05:43:33 pm
i do not mean to use Biot-Savart law which is computational expensive.

i am cheating using
analyticCurve3D

x = "0.5+0.5*Math.cos(theta)*Math.cos(0)-1*Math.sin(theta)*Math.sin(0)"
y = 0
z = "0+0.5*Math.sin(theta)*Math.sin(0)-1*Math.sin(theta)*Math.cos(0)"

transform "z:270d" etc to get the many lines i need.

is there a analyticCurve3D for array? which immediately draws the lines without ODE evolution.
thanks!