!!=============================================================================
!! MODULE rootFMM
!!=============================================================================
! Procedury Zeroin, BrentZero z knihy
! "Computer Methods for Mathematical  Computations",
! by George E. Forsythe, Michael A. Malcolm, and Cleve B. Moler
! Prentice-Hall, 1977.
!
! Prepis pro Fortran 90:
! Last updated: 28 February 2005 by Ralph Carmichael ralph@pdas.com 
! Public Domain Aeronautical Software 
! P.O. Box 1438 Santa Cruz CA 95061 USA 
!
! Upravy pro g95
! Jan Cely, UFKL,Prirodovedecka fakulta MU, unor 2007
! Verse 1.0 (rootFMMVer="1.0"), unor 2008
! 
!******************************************************************************
!
!	Moduly vytvorene z procedur v FMM se ukladaji do knihovny libFMM
!
!!=============================================================================
!!	V procedurach REAL(SP|DP) znaci single|double precision
!!=============================================================================
!!	FUNCTION Zeroin(a,b,F,tol) result(z)
!!		Vraci koren z rovnice F(x)=0 v intervalu <a,b> s presnosti tol
!!	VSTUP
!!	a, b	okraje intervalu v nemz se hleda koren F(x)=0
!!	F		funkce F(x) deklarovana takto
!!				FUNCTION F(x) RESULT(g)
!!					IMPLICIT NONE
!!					INTEGER,PARAMETER :: FP = selected_real_kind(X)
!!					REAL(FP),INTENT(IN):: x
!!					REAL(FP):: g
!!				END Function F
!!			kde FP = SP|DP je-li X = 4|8
!!	tol		velikost intervalu v nemz se pozaduje lokalizace korene
!!-----------------------------------------------------------------------------
!!	SUBROUTINE BrentZero(ax,bx,F,tol,maxIter,neval,errCode,xZero,fZero)
!!		Brentova modifikace Zeroin (proceduru vola i Zeroin)
!!	VSTUP
!!	ax, bx		viz a, b v Zeroin
!!	F			viz F v Zeroin
!!	tol			viz tol v Zeroin
!!	maxIter		maximalni povoleny pocet iteraci, dobra hodnota je 25
!!	VYSTUP
!!	neval		INTEGER, zde se nevyuziva, musi byt ale deklarovana a dosazena
!!	errCode		INTEGER, 0 = OK, 1 = prilis mnoho iteraci, 2 = F(ax)*F(bx)>0
!!	xZero		REAL(FP), nalezena hodnota korene, FP = SP|DP
!!	fZero		REAL(FP), F(xZero)
!!=============================================================================