SCIRun User Mailing List

## [SCIRUN-USERS] Re: Re: integral calculation in SCIRun

• From: Dana Brooks <brooks@ece.neu.edu>
• To: Jess Tate <jess@sci.utah.edu>
• Cc: Marta Nobre <marta_rnobre@hotmail.com>, "scirun-users@sci.utah.edu" <scirun-users@sci.utah.edu>
• Subject: [SCIRUN-USERS] Re: Re: integral calculation in SCIRun
• Date: Tue, 30 Apr 2013 15:39:43 -0400

 Marta hi, just to add to this --- if you have a FE model, with values at the mesh vertices, then the FE basis functions might give you a better way to integrate than just the point method Jess suggests if that is not accurate enough -- I'm not sure how to do this in SCIRun but if you tell us that is what you need to do we can probably work something out. Can you perhaps tell us a little about the problem you are working on (and where you are working on it) ? best, Dana Brooks On 4/29/13 2:22 PM, Jess Tate wrote: 575AC267-B5B5-4A38-902F-437CB0B9760B@sci.utah.edu" type="cite"> Hi Marta, There is an integrate option in the MapDataOntoElements that will integrate data over each volume element as it maps the data onto it.  It sounds like this is not what you need, though.   I assume that you have a mesh for each structure that you are interested in.  In this case you could calculate a simple integral by performing the product of data of each element wight he volume of each element, then summing the resulting data.  In your case you can use the CalculateDistanceToField module to get a value for the distance to the point of rotation, then use ReportFieldGeometryMeasures to get the volume of each element, and CalculateFieldData to multiply these together ( there are other ways to do it too).  You would then use GetFieldData and ReportColumnMeasure to sum all the data together and the resulting 1x1 matrix would be your integral.  This method will give a good value if your elements are small enough.  If you are looking for something more complex than this or something like a finite volume solver, these aren't really implemented in SCIRun currently.   Hopefully that helps.   cheers, Jess On Apr 29, 2013, at 9:02 AM, Marta Nobre wrote: Hello,   First time user here. Is there a way to calculate a volume integral in Scirun? We need to calculate the inertia tensor of some anatomical segments and were wondering if Scirun allows us to do the volume integrals once the mesh is built. Thanks in advance, Marta Nobre