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Hi Marios,<br>
<br>
<blockquote type="cite"> If I apply the
InterpolatetoQuadraturePoints filter as shown in Figure 2 the
output result is<br>
basically empty. </blockquote>
If you write the data arrays containing the scalar values at the
Gauss points to the file then you do not want to apply the
"interpolate to qp" filter. This filter's purpose is to generate
these array from nodal values. This means that you have to have the
nodal values. You mentioned that you've removed them so that you
won't get confused, and that will prevent this filter from working.<br>
<br>
<blockquote type="cite">If I apply the GenerateQuadraturePoints
filter as shown in Figure 3 the field data<br>
transformed to point data. Hence after the application of the
GenerateQuadraturePoints the previous 9<br>
point data and 4 cell data are not exist anymore but together with
the field data they transformed to 16<br>
point data representing the 16 Gauss points. Those 16 points have
the correct coordinates and T values.<br>
</blockquote>
yes, that's what should happen. You're visualizing a different
geometry - the Gguass points - so data arrays on the original
geometry will not be available.<br>
<br>
<br>
<blockquote type="cite"> I tried to reproduce the same
example using the GID software and the results are shown in<br>
Figure 4. Can I do something similar with Paraview? I want to have
these contour lines instead of just<br>
point’s information. I want to continue use Paraview because has
some really powerful features that I<br>
like and I am sure this is trivial but I cannot find some way to
do it.<br>
</blockquote>
you can't generate the contours on a point set, you first need to
mesh it. One way to do this would be to apply "delaunay 2d" to the
point set. Other approaches would be more efficient and produce
better results but would require you to write some code. eg. write
out the mesh on the Gauss points directly from your simulation. <br>
<br>
<br>
<div class="moz-cite-prefix">On 12/04/2013 10:30 AM, Marios Mavros
wrote:<br>
</div>
<blockquote
cite="mid:CA+0nUO9Hg4-F-Y2+sxLVGReh5nkGquT0ByttbNzrw3LEGs_f1A@mail.gmail.com"
type="cite">
<div dir="ltr">Hi Burlen,
<div><br>
</div>
<div>Thank you for your help and for your example that you have
provided. I followed your instructions and I prepare a small
pdf explaining what I did and what I expected as a final
result. I thought that this procedure was the solution to my
problem but maybe I have to do something extra or something
different. Attached you will find also the file that I used. </div>
<div><br>
</div>
<div>Thank you again for your help</div>
<div><br>
</div>
<div>Marios </div>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Tue, Dec 3, 2013 at 2:46 AM, Burlen
Loring <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:bloring@lbl.gov" target="_blank">bloring@lbl.gov</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<div class="im"> <br>
<blockquote type="cite">1. What the numbers 0 4 8 12
(line 24) represent?</blockquote>
</div>
This is the offset array used by VTK for random access
into data on the quadrature points data. To generate it
you go cell by cell and accumulate the number of
quadrature points used by each cell. The next cell's data
offset is the sum of the previous cell's number of
quadrature points.<br>
<br>
note that the documentation says that each array has a
quadrature scheme dictionary, but this changed. the
dictionaries are stored in the offeset array. we did this
so that you only need to define one quadrature scheme
dictionary for many arrays.
<div class="im"><br>
<br>
<blockquote type="cite">2. What the QuadratureWeights
are all zero (line 37)?</blockquote>
</div>
Those aren't currently used in VTK but we have a place
holder for them in case they are needed in user developed
custom filters or later in VTK.
<div class="im"><br>
<br>
<blockquote type="cite">3. In your example there are 4
cells with 4 Gauss points in each cell. In total 16
Gauss points. If I want to assign to each Gauss point
one value of stress or strain how I have to write
those 16 values in xml format.</blockquote>
</div>
in my example you would read this file into PV and apply
"interpolate to quadrature points" and then "generate
quadrature points".<br>
<br>
You're asking about writing the data on the Gauss points
into the file. You have to store them in VTK FieldData and
add an information key to each array that names the offset
array. You have to order them correctly according to the
offsets array and quadrature scheme. for example the pdf I
sent before shows how each cell's quadrature points are
ordered for one scheme. you won't write the points
themselves, just the data values.<br>
<br>
the T FieldData array in the following file is an example
of containing scalar values at quadrature points (watch
out there's also a PointData array named T that stores the
nodal values),
<a moz-do-not-send="true"
href="http://www.hpcvis.com/vis/images/vtk-quadrature-points-example/quadrature-points-example-2.vtu"
target="_blank">http://www.hpcvis.com/vis/images/vtk-quadrature-points-example/quadrature-points-example-2.vtu</a><br>
<br>
after reading such a file into PV, you could see the
arrays in the spreadsheet view but to see them in the
2d/3d view you'll need to apply the "generate quadrature
points" filter to produce the point set and transfer the
data onto it.
<div>
<div class="h5"><br>
<br>
<div>On 12/01/2013 10:26 PM, Marios Mavros wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">Hi Burlen,
<div><br>
</div>
<div>Your example was really helpful to understand
many thing about the xml format and I want to
thank you about that, but I still have some
questions.</div>
<div><br>
</div>
<div>1. What the numbers 0 4 8 12 (line 24)
represent?</div>
<div>2. What the QuadratureWeights are all zero
(line 37)?</div>
<div>3. In your example there are 4 cells with 4
Gauss points in each cell. In total 16 Gauss
points. If I want to assign to each Gauss point
one value of stress or strain how I have to
write those 16 values in xml format. Can you
please sent me an example with this information?</div>
<div><br>
</div>
<div>Thank you very much </div>
<div><br>
</div>
<div>Marios</div>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Sat, Nov 30, 2013 at
4:28 PM, Burlen Loring <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:bloring@lbl.gov"
target="_blank">bloring@lbl.gov</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0
0 0 .8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>Hi Mario,<br>
<br>
sending again to the list. the weights
have 2 dimensions i (node id) and j (Gauss
point id), so to generate
ShapeFunctionWeights for a new
QuadratureSchemeDefinition what you do is
evaluate each shape function at each Gauss
point. For the linear quadrilateral you'll
end up with 16 weights. For example see
the example<br>
<br>
<a moz-do-not-send="true"
href="http://www.hpcvis.com/vis/images/vtk-quadrature-points-example/vtk-quadrature-points-example.pdf"
target="_blank">http://www.hpcvis.com/vis/images/vtk-quadrature-points-example/vtk-quadrature-points-example.pdf</a><br>
<a moz-do-not-send="true"
href="http://www.hpcvis.com/vis/images/vtk-quadrature-points-example/quadrature-points-example.vtu"
target="_blank">http://www.hpcvis.com/vis/images/vtk-quadrature-points-example/quadrature-points-example.vtu</a><span><font
color="#888888"><br>
<br>
Burlen</font></span>
<div>
<div><br>
<br>
On 11/29/2013 3:34 PM, Marios Mavros
wrote:<br>
</div>
</div>
</div>
<div>
<div>
<blockquote type="cite">
<div dir="ltr">Hi Burlen,
<div><br>
</div>
<div>I want to thank you for the
information that you send me. I
read the paper and I try to made a
simple example in xml format for a
4 node quadrilateral element but
it didn't work for me. Attached
you will find the element
formulation that I used with the
shape functions and a .vtu file
with my example. If I want to give
4 stress values in the 4 Gauss
points ( lets say 0.1 0.2 0.4
-0.1) can you please write in the
.vtu file the missing information
in order to understand haw I have
to write a correct file in xml
format.</div>
<div><br>
</div>
<div>Thank you very much</div>
<div><br>
</div>
<div>Marios Mavros</div>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Wed, Nov
27, 2013 at 2:56 PM, Burlen Loring
<span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:bloring@lbl.gov"
target="_blank">bloring@lbl.gov</a>></span>
wrote:<br>
<blockquote class="gmail_quote"
style="margin:0 0 0
.8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div text="#000000"
bgcolor="#FFFFFF"> You'll need
to use an XML file format.
There's some documentation in
the following link. It's
slightly dated but should get
you started. <a
moz-do-not-send="true"
href="http://www.vtk.org/Wiki/images/7/78/VTK-Quadrature-Point-Design-Doc.pdf"
target="_blank">http://www.vtk.org/Wiki/images/7/78/VTK-Quadrature-Point-Design-Doc.pdf</a><br>
The ctest,
VTK/Filters/General/Testing/Cxx/TestQuadraturePoints.cxx,
could be used as an example.
<div>
<div><br>
<br>
<div>On 11/27/2013 02:32
PM, Marios Mavros wrote:<br>
</div>
</div>
</div>
<blockquote type="cite">
<div>
<div>
<div dir="ltr">Hi
<div><br>
</div>
<div>I have wrote a
simple program in
Fortran that
transform the output
of a finite element
software in vtk
Legacy Format. I
don't know how to
handle the Gauss
points values. For
example in my case
my cells have 4
Gauss points and I
have 4 values (for
example strain in
x-direction) for
each cell. How I
have to write the
vtk file taking into
account that each
cell has many Gauss
points?</div>
<div><br>
</div>
<div>Thank you</div>
<div><br>
</div>
<div>Marios </div>
</div>
<br>
<fieldset></fieldset>
<br>
</div>
</div>
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