SCIRun User Mailing List

Text archives Help

Re: [SCIRUN-USERS] ModifyConductivities

Chronological Thread 
  • From: David Weinstein <>
  • To: Grégoire Walckiers <>
  • Cc:
  • Subject: Re: [SCIRUN-USERS] ModifyConductivities
  • Date: Tue, 27 Sep 2005 15:51:56 -0600

Hi Gregoire,

There are two answers to your question:

1) For the purposed of FEM simulations, SCIRun supports Fields with conductivity tensors stored either:
a) explicitly -- at each element, there's a Tensor (i.e. the data is a Field<Tensor>)
b) as a look-up table -- at each element there's an integer (Field<int>), and the Field contains a Property called conductivity_table which is the lookup table that maps integers to Tensors.

The SCIRun modules that set up Finite Element systems are capable of handling both of these formats. So, often times users will use b) since it takes up less space if you have a small number of unique Tensors (i.e. a heterogeneous model made up of isotropic compartments).

2) Occasionally, someone will want to convert a model from format a) to format b), or vice-versa. For example, the ShowField visualization module requires that tensors be stored in format a). For this purpose, we have two modules that implement converting back and forth. Both are located in the BioPSE::Forward category -- they're called IndicesToTensors and TensorsToIndices.


On Sep 27, 2005, at 7:27 AM, Grégoire Walckiers wrote:

Hi all

I don't understand how to use the ModifyConductivities Module. According to the module reference, it should have as Field Input a field were each cell value is a int and as Matrix Input a matrix of size N*9 where N is at least greater than the number of different index in the Input field.
I made a net corresponding to the net in the BioFEM tutorial but the Field Output of the ModifyConductivities is still a TetVolField of int.
Is it possible to get in output a Field of Tensor using this module?
In the module reference, it is said that the /"The tensors are stored as a 'conductivities' property in the input and output fields."
/How do you manage this property of the field (using SetProperty doesn't seem to work).

thanks a lot


====================================================================== =====
== The SCIRun Users mailing list: send email to ==
== for more details. ==
== Please acknowledge use of SCIRun in your papers and reports: ==
== see biopse_citation.bib ==
====================================================================== =====

== The SCIRun Users mailing list: send email to   ==
== for more details.                                                     ==
== Please acknowledge use of SCIRun in your papers and reports:          ==
==   see         ==

Archive powered by MHonArc 2.6.16.

Top of page