Matrix-Powers CG (MPCG) seems to be working for a single outer iteration.
The matrix powers kernel with Nstep = 2 now works, but it's still
a complete mess. The formulation presented in Hoemenn's PhD thesis
is incorrect.
Got Matrix-powers CG working.
Beginning to clean-up matrix-powers CG
Merged the j=0 and j!=0 loops of the Matrix-powers CG. Substantial
cleanup.
Now use the Gram matrix to compute r2 and rAr in each iteration.
The Gram matrix is currently stored as a complex 2d array, but
only the real components are actually used.
Now store the Gram matrix in a 2d array of doubles
Removed the MPCG3 solver, which was for testing purposes.
The Matrix-powers CG solver now returns the correct value of x.
Need to refine the stopping criterion a bit.