The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Software » comp.soft-sys.matlab

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: volume integration
Replies: 11   Last Post: May 7, 2014 7:25 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Marios Karaoulis

Posts: 89
Registered: 5/10/10
Re: volume integration
Posted: Sep 6, 2011 5:51 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

On Sep 6, 1:04 pm, "Bruno Luong" <> wrote:
> Marios Karaoulis <> wrote in message <>...
> > Hi all,
> > I have two vector field J1 and J2, in 3D space (x,y,z) and calculated
> > at some discrete points (extracted in a txt file from comsol.

> > I need to volume integrate the
> > triple_integration of (J1 dot J2), which is expressed as

> > triple_integration ( J1(x)*J2(x) + J1(y)*J2(y) + J1(z)*J2(z) ).
> > I have found that
> > , but in my case, I have no analytically expression of the funstion.
> > I guess I could interpolate using TriScatinterp, but is any other way
> > to do that?

> You could you partition the volume by Delaunay tetrahedron (help DelaunayTri). Over each tetrahedron Tj, approximate the integral by:
> Ij = |Tj|/4 sum(i) dot(J1,J2)(xi)
> where {xi}={x1,x2,x3,x4} are four corners of Tj. and |Tj| is the volume
> |Tj| = 1/6*abs(det [x2-x1 x3-x2 x4-x2 ]).
> Then sum Ij for all j to get the integral on the whole volume.
> Bruno

Thanks for the reply. I am not sure I get this, but I will give it a
By DelaunayTri, you create triangles. Should't I need delaunayn ?


Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.