SNESQuadraticLineSearch

Performs a quadratic line search.

int SNESQuadraticLineSearch(SNES snes,void *lsctx,Vec x,Vec f,Vec g,Vec y,Vec w,PetscReal fnorm,PetscReal *ynorm,PetscReal *gnorm,int *flag)

Collective on SNES and Vec

	snes	- the SNES context
	lsctx	- optional context for line search (not used here)
	x	- current iterate
	f	- residual evaluated at x
	y	- search direction (contains new iterate on output)
	w	- work vector
	fnorm	- 2-norm of f

	g	- residual evaluated at new iterate y
	y	- new iterate (contains search direction on input)
	gnorm	- 2-norm of g
	ynorm	- 2-norm of search length
	flag	- 0 if line search succeeds; -1 on failure.

-snes_ls quadratic -Activates SNESQuadraticLineSearch()

Use SNESSetLineSearch() to set this routine within the SNESLS method.

SNES, nonlinear, quadratic, line search