From: Sven Hammarling
Date: Wed, 06 Sep 2006 13:31:21 +0100
The EISPACK routine cg is a very well tried and tested routine, so it is
almost certain that you are calling it incorrectly. Note that you have
to supply the matrix A as two separate real (double precision) arrays,
one for the real parts, the second for the imaginary parts.
The modern equivalent of EISPACK is LAPACK see:
Routine DGEEV is the LAPACK equivalent of cg.