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Re: Curl and Div problems

  • To: mathgroup at smc.vnet.net
  • Subject: [mg115526] Re: Curl and Div problems
  • From: Bob Hanlon <hanlonr at cox.net>
  • Date: Thu, 13 Jan 2011 03:29:18 -0500 (EST)

Use the defined coordinate system

Needs["VectorAnalysis`"]

sub = Thread[{x, y, z} -> Coordinates[]]

{x -> Xx, y -> Yy, z -> Zz}

D[x^2 y, x] + D[x z, y] + D[x^2 y^3, z]

2 x y

Div[{x^2 y, x z, x^2 y^3} /. sub] /. (Reverse /@ sub)

2 x y

Div[{Xx^2 Yy, Xx Zz, Xx^2 Yy^3}]

2 Xx Yy

Curl[{x^2 y, x z, x^2 y^3} /. sub] /. (Reverse /@ sub)

{-x + 3*x^2*y^2, -2*x*y^3, -x^2 + z}

Curl[{Xx^2 Yy, Xx Zz, Xx^2 Yy^3}]

{-Xx + 3*Xx^2*Yy^2, -2*Xx*Yy^3, -Xx^2 + Zz}


Bob Hanlon

---- sean k <seaninsocal at gmail.com> wrote: 

=============
I'm having problems with VectorAnalysis package.

Within the documentation center, the package loads and works fine.

But in a notebook, it seems to highlight Curl in red and neither Div
or Curl works properly.

Needs["VectorAnalysis`"]

{D[x^2 y, x] + D[ x z, y] + D[ x^2 y^3, z]}

Div[{x^2 y, x z, x^2 y^3}]

gives different answers.

{2 x y}
0


Curl[{x^2 y, x z, x^2 y^3}]

gives

{0,0,0}


I'm on windows vista home edition, 64 bit, Mathematica 8.0.

Does anyone else have this problem?




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