Package spai: Information

Source package: spai
Version: 3.2-alt9
Build time:  Apr 15, 2023, 08:13 PM
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License: GPLv2
Summary: SParse Approximate Inverse Preconditioner
Description: 
Given a sparse matrix A the SPAI Algorithm computes a sparse approximate inverse
M by minimizing || AM - I || in the Frobenius norm. The approximate inverse is
computed explicitly and can then be applied as a preconditioner to an iterative
method. The sparsity pattern of the approximate inverse is either fixed a priori
or captured automatically:

  * Fixed sparsity: The sparsity pattern of M is either banded or a subset of
  the sparsity pattern of A.
  * Adaptive sparsity: The algorithm proceeds until the 2-norm of each column of
  AM-I is less than eps. By varying eps the user controls the quality and the
  cost of computing the preconditioner. Usually the optimal eps lies between 0.5
  and 0.7.

A very sparse preconditioner is very cheap to compute but may not lead to much
improvement, while if M becomes rather dense it becomes too expensive to
compute. The optimal preconditioner lies between these two extremes and is
problem and computer architecture dependent.

The approximate inverse M can also be used as a robust (parallel) smoother for
(algebraic) multi-grid methods.

List of rpms provided by this srpm:
libspai (e2kv6, e2kv5, e2kv4, e2k)
libspai-debuginfo (e2kv6, e2kv5, e2kv4, e2k)
libspai-devel (e2kv6, e2kv5, e2kv4, e2k)
libspai-devel-doc (noarch)
spai (e2kv6, e2kv5, e2kv4, e2k)
spai-debuginfo (e2kv6, e2kv5, e2kv4, e2k)



    1. gcc-fortran
    2. openmpi-devel
    3. liblapack-devel

Last changed


Sept. 22, 2021 Grigory Ustinov 3.2-alt9
- Fixed FTBFS.
Sept. 17, 2020 Grigory Ustinov 3.2-alt8
- Fixed FTBFS.
Aug. 12, 2012 Eugeny A. Rostovtsev 3.2-alt7
- Built with OpenBLAS instead of GotoBLAS2