Hi, <br> This is not really a bug, but just what the linear precision integration does. As you can see in vtkIntegrateAttributes.cxx:215, the quad cell is basically cut into two triangles along a diagonal, integration is done for each triangle and the results are added up. So, depending where your "1" falls on a diagonal vertex, you will get different results.<div>
<br></div><div>Leo</div><div><br></div><br><div class="gmail_quote">On Sat, Jun 9, 2012 at 8:57 AM, Magician <span dir="ltr"><<a href="mailto:f_magician@mac.com" target="_blank">f_magician@mac.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi all,<br>
<br>
<br>
Now I found a bug of the filter.<br>
<br>
My ParaView's version is 3.14.1.<br>
I define node names as below:<br>
> c--d<br>
> | |<br>
> a--b<br>
<br>
Case 1: a=1.0, b=0.0, c=0.0, d=0.0<br>
Integration Value = 0.33333<br>
<br>
Case 2: a=0.0, b=1.0, c=0.0, d=0.0<br>
Integration Value = 0.16666<br>
<br>
Case 3: a=0.0, b=0.0, c=1.0, d=0.0<br>
Integration Value = 0.16666<br>
<br>
Case 4: a=0.0, b=0.0, c=0.0, d=1.0<br>
Integration Value = 0.33333<br>
<br>
So Integration Values are calculated as (2*a+b+c+2*d)/6.<br>
I think it's not a good result.<br>
<span class="HOEnZb"><font color="#888888"><br>
<br>
Magician<br>
</font></span><div class="HOEnZb"><div class="h5"><br>
<br>
On 2012/06/08, at 12:54, Magician wrote:<br>
<br>
> Hi all,<br>
><br>
><br>
> I'm now comparing integration results of each postprocessors.<br>
> I made a simple Quadratic VTK model as below:<br>
>> # vtk DataFile Version 2.0<br>
><br>
>> QuadCell<br>
>> ASCII<br>
>> DATASET UNSTRUCTURED_GRID<br>
>> POINTS 4 FLOAT<br>
>> 0 0 0<br>
>> 1 0 0<br>
>> 0 1 0<br>
>> 1 1 0<br>
>> CELLS 1 5<br>
>> 4 0 1 3 2<br>
>> CELL_TYPES 1<br>
>> 9<br>
>> POINT_DATA 4<br>
>> SCALARS scalar FLOAT 1<br>
>> LOOKUP_TABLE DEFAULT<br>
>> 0.0<br>
>> 1.0<br>
>> 2.0<br>
>> 4.0<br>
><br>
> When I apply Point Data to Cell Data filter,<br>
> scalar values are interpolated as 1.75.<br>
> It may be calculated as (0.0+1.0+2.0+4.0)/4.0.<br>
><br>
> But when I apply Integrate Variables filter,<br>
> scalar value is integrated as 1.833....<br>
> The area value of quadratic cell is 1.0, so I thought<br>
> integrated values should be equal to cell data.<br>
><br>
> How the integrated value is calculated?<br>
><br>
><br>
> Magician<br>
<br>
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