Thanks for information, I appreciate it. In the days between the original post and this, a co-worker who is much more a dx guru than I, managed figured out much of what you detail for me. The main problem I was experiencing was due to the fact that I have time series data, and I needed to tell it to grab only one series at a time. Once we got beyond that, everything else fell into place. We pass the velocity field to streamline in the first input. For the starting positions, we "Mark" the "positions" of the data stream coming out of the import box and use that. Seems reasonable.
Only problem is that the streamlines do not all connect back on one another, which is not quite what I am used to. In quiet regions of the flow field, some of them look like tracer particle paths that just stop. I am not sure if anything can be done about this. Maybe you could comment ... I looked on the streamline manual page and it seems that the algorithm it uses to calculate the streamlines is to calculate particle paths in space, based on the velocity field at a point, rather than computing the curl, and calculating the streamline contours from the vorticity.
I'll try your suggestions in regard to Ribbon and Tube ...
Thanks!
Fred Phelan
At 10:12 AM 7/8/02 -0400, you wrote:
>
>Very little. It must be a valid velocity field - eg. have 3-D positions,
>elements (cubes or tets), and vectors, or 2-D positions, elements
>(triangles or quads) and vectors. If so, you can simply send it in to the
>first input of Streamline. Without any other specifications, the
>streamline will start at the centerpoint of the vector field and proceed
>from there. Pass its result into Image. For more info, you could first
>pass the result of streamline through AutoColor and it'll get the default
>color map indicating the magnitude of the velocity at each point along the
>streamline. Collecting the output of streamline with maybe ShowBox of the
>vector field before Image might be better. Pass the Streamline through
>Tube or, if the curl of the vector field is interesting, Ribbon would also
>be good. You can specify a non-default starting point several ways, such
>as a vector interactor or a Probe. Past this, the options become endless.
>
>Greg
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> "Frederick R. Phelan Jr."
>
> <[EMAIL PROTECTED]> To:
>[email protected]
> Sent by: cc:
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> [EMAIL PROTECTED] Subject:
>[opendx-users] Streamline Module
> son.ibm.com
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> 07/03/2002 09:31 AM
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> Please respond to
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> opendx-users
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>Simple question . . . if I have some 3-D velocity data, what kind of
>manipulation do I need to do to send it through the streamline module and
>view the streamlines? Assume simple grid.
>
>Thanks.
>Frederick R. Phelan Jr., Ph.D.
>Multiphase Materials Group
>Polymers Division
>National Institute of Standards and Technology
>NIST, Bldg. 224/Rm. B108
>100 Bureau Dr., STOP 8543
>Gaithersburg, MD 20899-8543
>301.975.6761 (VOX)
>301.975.4932 (FAX)
>[EMAIL PROTECTED]
>http://www.nist.gov/frederick_phelan
>
>
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>
Frederick R. Phelan Jr., Ph.D.
Multiphase Materials Group
Polymers Division
National Institute of Standards and Technology
NIST, Bldg. 224/Rm. B108
100 Bureau Dr., STOP 8543
Gaithersburg, MD 20899-8543
301.975.6761 (VOX)
301.975.4932 (FAX)
[EMAIL PROTECTED]
http://www.nist.gov/frederick_phelan
