B.3. Matrix File

The options are:

	MFMAT=1 PROFILE SOLVER Accounts for the sparsity of matrix [A] on an equation by equation basis. Typical applications include finite element and finite difference programs.
	MFMAT=2 BLOCK SOLVER Divides the matrix [A] into square blocks, accounting for sparsity on a block by block basis. This solver uses industry standard BLAS3 kernels and provides excellent I/O performance on extremely large problems. Typical applications include boundary integral and moment method programs.
	MFMAT=3 SLAB SOLVER Extends the functionality of the Block Solver by providing full column partial pivoting for full nonsymmetric matrices.

When you create a matrix file, FMS completes the Matrix File Attribute List , LUA(25), which you provide. This array contains all the information FMS needs to manage the matrix file.

FMS uses four files to store the data for each matrix:

• Lower Triangle Data File, LUA(1)
  Stores the terms in the lower triangle [Al].

• Diagonal Data File, LUA(2)
  Stores the terms on the diagonal as a single vector, {D}. You may read and write this data using FMSRED and FMSWRT.

• Upper Triangle Data File, LUA(3)
  Stores the terms in the upper triangle [AU]. This file is not used for symmetric matrices.

• Integer Data File, LUA(4)
  Stores all integer pointers necessary to access the file.