Integrate in cylindrical
- To: mathgroup at smc.vnet.net
- Subject: [mg122907] Integrate in cylindrical
- From: Alexander <alexmag25 at hotmail.com>
- Date: Tue, 15 Nov 2011 05:51:27 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
Hello dear community, I am running into some difficulty with integration, When I integrate the following expression in Cartesian coordinates it seems I get result as expected, h := {hx[x, y, z], hy[x, y, z], hz[x, y, z]} ; fe = Integrate[ f[x, y, z] Grad[ Div[h*DiracDelta[x - a, y - b, z - c], Cartesian[x, y, z]], Cartesian[x, y, z]], {x, -Infinity, Infinity}, {y, -Infinity, Infinity}, {z, -Infinity, Infinity}, Assumptions -> Element[{a, b, c}, Reals]] However exact same expression in cylindrical coordinates gives me error message Integral does not converge, Needs["VectorAnalysis`"] h := {hr[r, \[Phi], z], h\[Phi][r, \[Phi], z], hz[r, \[Phi], z]}; fe = Integrate[ f[r, \[Phi], z] Grad[ Div[h*r*DiracDelta[r - a, \[Phi] - b, z - c], Cylindrical[r, \[Phi], z]], Cylindrical[r, \[Phi], z]] r, {r, 0, Infinity}, {\[Phi], 0, 2 \[Pi]}, {z, -Infinity, Infinity}, Assumptions -> Element[{a, b, c}, Reals] && r > 0 && 0 < b < 2 \[Pi]] any hint/help/comment would be greatly appreciated, thanks. Alex