Visualizing Staggered Vector Fields

VisIt, a visualization tool used by scientific codes (VORPAL, CHOMBO, etc.) in plasma physics, astrophysics, electromagnetic wave and climate modeling, is the premier visualization tool funded by DoE. VisIt runs on leadership class facilities and is capable of handling extremely large datasets. However, VisIt & apos;s current data model only allows for node and cell based data; data located at different positions within a cell, such as those arising in C and D Arakawa meshes, or Yee meshes are not supported. Failing to correctly support Yee and Arakawa C/D meshes can lead scientists to misinterpret data due to spurious visualization effects, such as an electric field that is not perpendicular to a conducting surface or the spiraling of a divergence-free field. This project is about extending VisIt so as to represent accurately face and edge centered fields, which are used in finite-element, finite-volume, and finite-difference discretization schemes. We will develop an input format that will allow data to be attached to faces and edges in addition to vertices and cells. Next we will improve the streamline filter so as to use the vector field components at their true location. The integration of field lines will be provided by a third party library (e.g. Sundials/CVODE) or by a symplectic integrator, which will exactly satisfy the divergence condition of some vector fields. Commercial Applications and Other Benefits: This project will primarily benefit VisIt and the hundreds of applications using VisIt as their visualization engine. CHOMBO is one such application, funded by DoE. The commercial VORPAL code is another VisIt application that will benefit from this work through increased sales and revenues from consulting