The Cholesky test program generates random symmetric positive definite band or tridiagonal test matrices with values in the interval [-1,1]. It then calls the ScaLAPACK routines to factor and solve the system, and computes a solve residual error check to verify that each operation has performed correctly.

Specifically, each test matrix is subjected to the following tests:

- Compute the Band or Tridiagonal LLT factorization using PxPBTRF (or PxPTTRF)
- Solve the system using PxPBTRS (or PxPTTRS), and compute the ratio
*SRESID*

Susan Blackford 2001-08-12