|
[Sponsors] |
August 17, 2004, 13:04 |
extreme points problem
|
#1 |
Guest
Posts: n/a
|
Hello, everyone Now here is a difficult for me and hope to be helped out. I have got scalar data at every grid point in a Cartesian coordinate and also found the positions of extreme points. The criteria for extreme points is
[S(i)-S(i+1)]*[S(i)-S(i-1)]>0, where i will be in x, y and z 3 directions. But we want to know more precisely the positions of extreme points so I tried to do interpolation and found some extreme points will dispear with the same criteria. This is due to the effect from no-adjencent points. For example, S(0,0,0) is extreme, then S(1,1,0), S(1,1,1),S(1,-1,0) are no-adjencent. So I wonder should I also consider these no-adjencent points, or only adjent points(totally they are S(0,0,1),S(0,0,-1),S(1,0,0),S(-1,0,0),S(0,1,0),S(0,-1,0)) for interpolation? Of course, more points considered, more reasonable. But more negative effect will destroy the criteria. How do you think about it? Great thanks |
|
August 17, 2004, 15:04 |
Re: extreme points problem
|
#2 |
Guest
Posts: n/a
|
The extrema may not coincide with any of the grid points. You can try to set up a finite-element interpolation and solve for grad(u)=0 to locate the extrema.
|
|
August 18, 2004, 04:15 |
Re: extreme points problem
|
#3 |
Guest
Posts: n/a
|
thanks a lot. The finite element interpolation you mentioned is for irregular gird? Because the mesh I used is Cartesian coordinate grid,FE interpolation is still good? How about it if compared with other kind of interpolation, like polynomial, B-spline etc? Thanks
|
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
[OpenFOAM] Paraview display problem | jiejie | ParaView | 4 | October 13, 2013 22:29 |
Problem with skew faces in simpleFoam... | HelloWorld | OpenFOAM | 7 | May 14, 2010 12:28 |
Velocity profiles problem behind the elbow (3D problem) | kabat73 | FLUENT | 8 | May 9, 2010 05:26 |
[Other] surfaceCheck problem | vivien | OpenFOAM Meshing & Mesh Conversion | 0 | May 7, 2010 05:24 |
Is this problem well posed? | Thomas P. Abraham | Main CFD Forum | 5 | September 8, 1999 15:52 |