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3 Structured-Grid System Interface (Struct)

 

In order to get access to the most efficient and scalable solvers for scalar structured-grid applications, users should use the Struct interface described in this chapter. This interface will also provide access (this is not yet supported) to solvers in HYPRE that were designed for unstructured-grid applications and sparse linear systems in general. These additional solvers are usually provided via the unstructured-grid interface (FEI) or the linear-algebraic interface (IJ) described in Chapters 5 and 6.

Figure 3.1 gives an example of the type of grid currently supported by the Struct interface. The interface uses a finite-difference or finite-volume style, and currently supports only scalar PDEs (i.e., one unknown per gridpoint).

  
Figure 3.1: An example 2D structured grid, distributed accross two processors.

There are four basic steps involved in setting up the linear system to be solved:

  1. set up the grid,
  2. set up the stencil,
  3. set up the matrix,
  4. set up the right-hand-side vector.
To describe each of these steps in more detail, consider solving the 2D Laplacian problem

 

Assume (3.1) is discretized using standard 5-pt finite-volumes on the uniform grid pictured in 3.1, and assume that the problem data is distributed across two processes as depicted.




next up previous contents index
Next: 3.1 Setting Up the Up: User's Manual Previous: 2.3 Which conceptual interface

Thomas Treadway
Fri Jul 27 10:01:25 PDT 2001