LCD method in KSP

Barry Smith bsmith at
Thu Oct 25 15:56:54 CDT 2007

  Oh, I see it is missing a manual page. I have just written one. Here it is

     KSPLCD -  Implements the LCD (left conjugate direction) method in PETSc.

   Options Database Keys:
+   -ksp_lcd_restart - number of vectors conjudate
-   -ksp_lcd_haptol - tolerance for exact convergence (happing ending)

   Level: beginner

   - J.Y. Yuan, G.H.Golub, R.J. Plemmons, and W.A.G. Cecilio. Semiconjugate
     direction methods for real positive definite system. BIT Numerical
     Mathematics, 44(1):189-207,2004.
   - Y. Dai and J.Y. Yuan. Study on semi-conjugate direction methods for
     non-symmetric systems. International Journal for Numerical Methods in
     Engineering, 60:1383-1399,2004.
   - L. Catabriga, A.L.G.A. Coutinho, and L.P.Franca. Evaluating the LCD
     algorithm for solving linear systems of equations arising from implicit
     SUPG formulation of compressible flows. International Journal for
     Numerical Methods in Engineering, 60:1513-1534,2004 
   - L. Catabriga, A. M. P. Valli, B. Z. Melotti, L. M. Pessoa,
     A. L. G. A. Coutinho, Performance of LCD iterative method in the finite
     element and finite difference solution of convection-diffusion
     equations,  Communications in Numerical Methods in Engineering, (Early

  Contributed by: Lucia Catabriga <luciac at>

.seealso:  KSPCreate(), KSPSetType(), KSPType (for list of available types), KSP,
           KSPCGSetType(), KSPLCDSetRestart(), KSPLCDSetHapTol()


  I know nothing beyond this.


On Thu, 25 Oct 2007, Keita Teranishi wrote:

> Hi,
> I am in trouble to find any document on a relatively new method called LCD in KSP even though it listed in the KSP_TYPE document.   I am wondering whether LCD is fully supported by the current version of  PETSc, 
> Thanks,
> ================================
>  Keita Teranishi
>  Math Software Group
>  Cray Inc.
>  keita at
> ================================

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