Dot Product with Vector Calculus, destroys function?

Posted on 2008-09-05 05:55 By gabourqu (2)

Categories:

Maple Commons general technical discussions

I'm running into a problem with Maple where DotProduct seems to destroy the functions it assigns.

I ran a simple case, and it seemed to work just fine: (dotproductproblem.mw)

However, my code seems to follow the exact same logic but doesn't want to work? Code is a simple check that a bessel function solution of current density follows Maxwell's Equations. (Cylinder_AC_test2.mw)

Maple 11.

Has anyone encountered this problem before? Or know what's wrong in the code I'm running? (code attached)

View 9242_Cylinder_AC_test2.mw on MapleNet or Download 9242_Cylinder_AC_test2.mw
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View 9242_dotproductproblem.mw on MapleNet or Download 9242_dotproductproblem.mw
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integration variable

Comment on 2008-09-05 10:54 from Alex Smith ( Maple Rating 3

300)

I believe the problem is in your definition of B:

B:=(r,t)-> int(-Curl(E(r,t),t);

Note that t is stretched between being a dummy variable on the right side and a honest variable on the left side.

So, try something like this:

B:=(r,t)->int(-Curl(E(r,tt),tt=0..t);

Thanks! that kind of

Comment on 2008-09-09 06:23 from gabourqu (2)

Thanks! that kind of works. In general this case is simple, since I explicitly know what the integration is. In order to evaluate and still get the same expression I was looking for, i would need something like:

B:=(r,t)->int(-Curl(E(r,tt),tt=infinity*sqrt(-1)..t); in order for the second term to evaluate to zero.

Weird kinda bug though. I've also experimented setting: tt=dummy..t and then dummy=-j*infinity but it still has problems evaluating limits. Error, (in limit) invalid limiting point.