Yes, DivCurl expects 3d data on 3d positions.  One workaround is too "fool"
DivCurl into thinking you have 3d positions is the following:

|
Mark(,"positions")
|
Compute(,[a.x,.a.y,0])
|
Unmark
|
DivCurl
|
Mark(,"positions")
|
Compute(,[a.x,.a.y])
|
Unmark
|
Compute(,a.z)  (to give you the z-component)
|

As you can tell this is not ideal.  An alternative would be to modify the
DivCurl code to handle 2d data.



Hans Fangohr <[EMAIL PROTECTED]>@opendx.watson.ibm.com on 04/24/2001
02:50:41 PM

Please respond to [email protected]

Sent by:  [EMAIL PROTECTED]


To:   [email protected]
cc:
Subject:  [opendx-users] Howto to compute DivCurl from 2d data?



Dear all,

I have a vector field with 3d data but the positions are 2d in the x-y
plane only (and the connections are quads). I.e. I have a 2d-plane of of
data, and at every data point there is a 3d vector.

I want to compute the curl of the field (really I only want the
z-component), but connecting the data to DivCurl gives
"ERROR: DivCurl: Operation not implemented: quads is an invalid
connections type"

I understand that it is hard for DivCurl to take the derivative of my data
with respect to z as I only have on value in this dimension. However, the
z-component of Curl should be computable since derivatives in x- and
y-direction can be obtained from my data.

Can anyone suggest a method that allows me to use the DivCurl module on my
data?

Or is it quicker to rewrite a special purpose DivCurl2d? (That would
involve taking derivates though, and I suspect DivCurl does this in a
clever way - so I would like to use it.)

Thanks in advance,

Hans


----------------------------------------------
Hans Fangohr

High Performance Computing Group
Department of Electronics and Computer Science
Building 59, Level 3, Room 3237
and
Quantum and Functional Matter Group
Department of Physics and Astronomy

University of Southampton
Highfield
Southampton
SO17 1BJ
Great Britain
[EMAIL PROTECTED]
----------------------------------------------




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