C ***********************************************************************
	PROGRAM GGRID
C
C  Two dimensional grid of spin dependent structure functions
C ***********************************************************************
	IMPLICIT NONE
	INTEGER iQ,nQ,iW,nW
	REAL*8	x,Q2,M,W,Wmin,Wmax,Wint
	PARAMETER (nQ=19,nW=202)
	REAL*8	Qgrid(nQ), Wgrid(nW)
	REAL*8	xG1Pgrid(nW,nQ),xG1Ngrid(nW,nQ),
     &		xG2Pgrid(nW,nQ),xG2Ngrid(nW,nQ)
	REAL*8	xg1p,Dxg1p,xg2p,Dxg2p, xg1n,Dxg1n,xg2n,Dxg2n

	M = 0.939D0	!GeV

	DO iQ=1,nQ
	  IF (iQ.LE.10) Qgrid(iQ) = DFLOAT(iQ)/10.D0
	  IF (iQ.GT.10) Qgrid(iQ) = DFLOAT(iQ)-9.D0
	  Q2 = Qgrid(iQ)


C...resonance region (M < W < 2 GeV)
	  Wmin = M
	  Wmax = 2.D0	!GeV
	  Wint = (Wmax-Wmin)/100
	  iW = 1
	  DO W=Wmin,Wmax,Wint

	    Wgrid(iW) = W

	    x = Q2/(Q2 + W**2 - M**2)

	    CALL G1G2P (x,Q2,xg1p,Dxg1p,xg2p,Dxg2p)
	    CALL G1G2N (x,Q2,xg1n,Dxg1n,xg2n,Dxg2n)
	print *, 'R: Q2,iW,W,x,g=',sngl(q2),iw,sngl(w),sngl(x),sngl(xg1p)

	    xG1Pgrid(iW,iQ) = xg1p
	    xG1Ngrid(iW,iQ) = xg1n
	    xG2Pgrid(iW,iQ) = xg2p
	    xG2Ngrid(iW,iQ) = xg2n

	    iW = iW + 1

	  ENDDO

C...DIS region (2 < W < 10 GeV)
	  Wmin = Wmax
	  Wmax = 10.D0	!GeV
	  Wint = (Wmax-Wmin)/100
	  DO W=Wmin,Wmax,Wint

	    Wgrid(iW) = W

	    x = Q2/(Q2 + W**2 - M**2)

	    CALL G1G2P (x,Q2,xg1p,Dxg1p,xg2p,Dxg2p)
	    CALL G1G2N (x,Q2,xg1n,Dxg1n,xg2n,Dxg2n)
	print *, 'D: Q2,iW,W,x,g=',sngl(q2),iw,sngl(w),sngl(x),sngl(xg1p)

	    xG1Pgrid(iW,iQ) = xg1p
	    xG1Ngrid(iW,iQ) = xg1n
	    xG2Pgrid(iW,iQ) = xg2p
	    xG2Ngrid(iW,iQ) = xg2n

	    iW = iW + 1

	  ENDDO

	ENDDO


c	if(.true.)stop
C...Write data to file
	OPEN (11, FILE='Ggrid.g1p', STATUS='UNKNOWN', FORM='FORMATTED')
	OPEN (12, FILE='Ggrid.g1n', STATUS='UNKNOWN', FORM='FORMATTED')
	OPEN (13, FILE='Ggrid.g2p', STATUS='UNKNOWN', FORM='FORMATTED')
	OPEN (14, FILE='Ggrid.g2n', STATUS='UNKNOWN', FORM='FORMATTED')
	WRITE (11,*) Qgrid, Wgrid, xG1Pgrid
	WRITE (12,*) Qgrid, Wgrid, xG1Ngrid
	WRITE (13,*) Qgrid, Wgrid, xG2Pgrid
	WRITE (14,*) Qgrid, Wgrid, xG2Ngrid
	CLOSE (11)
	CLOSE (12)
	CLOSE (13)
	CLOSE (14)
	WRITE (*,*) '... data written to file ...'
	END