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I found an SC15 poster that said all four dense symmetric tridiagonal eigensolvers (QR, divide and conquer, bisection and inverse iteration, and MRRR) were included in MAGMA. When I downloaded 2.0, however, I only saw the D&C driver. What is the actual status of the others?

- erjessup
**Posts:**1**Joined:**Thu Jun 02, 2016 11:32 pm

For the symmetric eigenvalue problem, the complex case (single-complex/double-complex) has a few more solvers than the real case.

zheevd -- divide and conquer

zheevdx -- divide and conquer, expert interface to compute portion of eigenvalues/vectors

zheevr -- MRRR

zheevx -- expert interface to compute portion of eigenvalues/vectors

If request all eval/vec, uses QR iteration (via dsterf or zsteqr).

If request portion of eval/vec, uses bisection and inverse iteration (via dstebz and zstein).

At the moment, the real case (single/double) has only divide and conquer solvers:

dsyevd -- divide and conquer

dsyevdx -- divide and conquer, expert interface

-mark

zheevd -- divide and conquer

zheevdx -- divide and conquer, expert interface to compute portion of eigenvalues/vectors

zheevr -- MRRR

zheevx -- expert interface to compute portion of eigenvalues/vectors

If request all eval/vec, uses QR iteration (via dsterf or zsteqr).

If request portion of eval/vec, uses bisection and inverse iteration (via dstebz and zstein).

At the moment, the real case (single/double) has only divide and conquer solvers:

dsyevd -- divide and conquer

dsyevdx -- divide and conquer, expert interface

-mark

Last edited by mgates3 on Sun Jun 05, 2016 6:52 am, edited 1 time in total.

**Reason:** *correction: heevx uses bisection + inverse iteration*

- mgates3
**Posts:**736**Joined:**Fri Jan 06, 2012 2:13 pm

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