[Paraview] Trying to plot signals to paraview

Wed Feb 4 13:21:17 EST 2009

Ken,

thank you for the answer, I'll check them. I already have the pdf and it is
useful.

Thanks a lot,
George Markomanolis

On Wed, Feb 4, 2009 at 5:50 PM, Moreland, Kenneth <kmorel at sandia.gov> wrote:

>  George,
>
> If you don't want to save the full image data, then either poly data or
> unstructured data is the way to go.  (Poly data will probably be a bit more
> efficient in ParaView, but either will work).
>
> If you are looking for a format to store the data in, you might consider
> the VTK legacy data format.  This format is documented in the VTK User's
> manual and here: http://www.paraview.org/Wiki/Image:VTK-File-Formats.pdf
>
> As far as the topology is concerned, you have a couple of options.  One is
> just to define a bunch of "vertices" (0D cells).  These will just appear as
> points on the screen.  The advantage is that they are easy to specify: You
> just need coordinates and the data at that coordinate.  The disadvantage is
> that they are just drawn as a series of points.  You run the risk of holes
> appearing between the cells once the resolution of the data drops below the
> pixel level.  (That might not be a concern for you.)  The other option is to
> draw quadrilaterals either centered on each point or connecting 4 points.
>  The quads will make sure that the space is filled but require you to
> specify more connectivity information.  In either case, a Delaunay
> triangulation seems unnecessarily complicated.
>
> -Ken
>
>
> On 2/4/09 10:20 AM, "George Markomanolis" <paraview at markomanolis.com>
> wrote:
>
> Dear Ken,
>
> First of all thank you for your time. Unfortunately I don't want to save
> all the data to the files. For example I must save (and load, plot) 8GB of
> full image than 500mb If i "erase" useless points. I have no idea about the
> duration to plot 8GB and 500mb at paraview but I believe it's big (general
> the useless points are 85-95% of full image). I'll try of course to check it
> but we've developed a technique to "erase" useless data and I believe that
> it won't be accepted from the team except if it is fast with paraview. For
> example with gnuplot in order to have good quality I save data to eps format
> and after I convert it to jpg (plotting is done at the cluster and we
> download only the jpg files) but the convert is very low, for example 500mb
> may take 10-15 minutes to plot and save. I'll try to plot full image. For
> unstructured grid I don't know how to declare topology, I believe I need
> something like delaunay (triangulation) at matlab?
>
> Thanks,
> George Markomanolis
>
> On Wed, Feb 4, 2009 at 4:18 PM, Moreland, Kenneth <kmorel at sandia.gov>
> wrote:
>
> ParaView is capable of reading in a regular grid of data, mapping a color
> to it, and drawing it scaled on the screen.  If your data is simply a raw
> array written to disk, then ParaView can read that in directly.  Does that
> basically solve your problem?
>
> There are two ways to "erase" the useless points.  The first way is to
> simply set the color map up so that these values are simply drawn in the
> background color.  The second way is to use the "Threshold" filter to remove
> the uninteresting points.  The Threshold filter will convert the data from a
> regular array to an unstructured grid.  A warning about using Threshold
> though: the unstructured grid it converts data to is a less efficient
> representation so it is possible to actually require more data for the
> result if not a lot is removed.
>
> -Ken
>
>
>
> On 2/4/09 2:30 AM, "George Markomanolis" <paraview at markomanolis.com <
> http://paraview@markomanolis.com> > wrote:
>
> Dear all,
>
> I am newbie to Paraview and I want to ask you something. I am working with
> signals and I use gnuplot for plotting. Unfortunately it's slow for big
> signals. Our program is parallel so we can create files of many GBs. We do a
> tricky parallel plot, every cpu plots a part of the signal, otherwise we
> couldn't see the image from gnuplot (crash). So when I saw paraview I liked
> a lot but it isn't easy.
>
> I must explain what I want to plot:
> We use a techinque in order to cut the points that haven't energy. For
> example a specific signal with 12000 x 12000 mesh of points which is 8GB
> file it can go under of 1GB if we cut the useless points. So I give at the
> gnuplot only the points that I want to plot x,y,z and I use pm3d map because
> I want them in 2D not 3D for example see the image:
> http://www.markomanolis.com/files/plots/plot.jpg
> I would like to ask. Is this unstructured grid? I show an easy signal it
> could be with more random points. I have tried unstructured grid for 2
> columns only and there is no surface between the columns. I used triangle
> strip and it was ok but I don't know if I could see the details like here
> (here I don't cut any useless point, in first image see wave details in the
> center):    http://www.markomanolis.com/files/plots/62_0_0.jpg ,
> http://www.markomanolis.com/files/plots/resFinal.jpg   .
> Could I have these plots with paraview or it is good with more complicated
> plots?
> I must write a script/ program to convert gnuplot file to paraview but I am
> not sure about the topology, I must declare the topolgy for every point,
> right?  I am confused because I have a lot of constrains for example if a
> point is alone then the topology is vertex if there is another point then
> line etc... Is there any way to plot this grid with something like image
> data. I want to give something like structured grid but NOT to give all the
> points (I don't need them).  The last two images I sent you are with all the
> points for education propose. I want to plot something like first image but
> witho more complicated topology
>
> Thank you for your time,
> George Markomanolis
>
>
>
>    ****      Kenneth Moreland
>     ***      Sandia National Laboratories
> ***********
> *** *** ***  email: kmorel at sandia.gov <http://kmorel@sandia.gov>
> **  ***  **  phone: (505) 844-8919
>     ***      web:   http://www.cs.unm.edu/~kmorel<http://www.cs.unm.edu/%7Ekmorel><
> http://www.cs.unm.edu/%7Ekmorel>
>
>
>
>
>
>    ****      Kenneth Moreland
>     ***      Sandia National Laboratories
> ***********
> *** *** ***  email: kmorel at sandia.gov
> **  ***  **  phone: (505) 844-8919
>     ***      web:   http://www.cs.unm.edu/~kmorel<http://www.cs.unm.edu/%7Ekmorel>
>
>
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