*DECK FLUGPT
      SUBROUTINE FLUGPT(IPRT,IPFLUX,IPTRK,IPMACR,IPFLUP,IPSOU,IFTRAK,
     1 IPSYS,IPHASE,ITPIJ,CXDOOR,TITLE,INITFL,LFORW,LEAKSW,IREBAL,
     2 NGRP,NMAT,NIFIS,NANIS,NLF,NLIN,NFUNL,OPTION,NUN,MAXINR,EPSINR,
     3 MAXOUT,EPSUNK,EPSOUT,IFRITR,IACITR,ILEAK,NREG,NSOUT,MATCOD,
     4 KEYFLX,VOL,REFKEF,NMERG,IMERG)
*
*-----------------------------------------------------------------------
*
*Purpose:
* Driver for Boltzmann equation solvers. Solution of a fixed source
* eigenvalue problem.
*
*Copyright:
* Copyright (C) 2008 Ecole Polytechnique de Montreal
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version
*
*Author(s): A. Hebert
*
*Parameters: input
* IPRT    print flag.
* IPFLUX  pointer to the flux LCM object.
* IPTRK   pointer to the tracking LCM object.
* IPMACR  pointer to the macrolib LCM object.
* IPFLUP  pointer to the unperturbed flux LCM object.
* IPSOU   pointer to the GPT fixed source LCM object.
* IFTRAK  tracking file unit number.
* IPSYS   pointer to the system LCM object (=0 for the method of
*         characteristics).
* IPHASE  1 for asm 2 for pij.
* ITPIJ   type of collision probability information available:
*         =1 scattering modified pij (wij);
*         =2 standard pij;
*         =3 scattering modified pij+pijk (wij,wijk);
*         =4 standard pij+pijk.
* CXDOOR  name of the flux solution door.
* TITLE   title.
* INITFL  flux initialization flag (=0/1/2: uniform flux/LCM/DSA).
* LFORW   flag set to .false. to solve an adjoint problem.
* LEAKSW  leakage flag (=.true. if leakage is present on the outer
*         surface).
* IREBAL  flux rebalancing flag (=1: perform rebalancing).
* NGRP    number of energy groups.
* NMAT    number of mixtures.
* NIFIS   number of fissile isotopes.
* NANIS   maximum cross section Legendre order.
* NLF     number of Legendre orders for the flux.
* NLIN    number of polynomial components in flux spatial expansion.
* NFUNL   number of spherical harmonics components.
* OPTION  type of leakage coefficients: 
*         'LKRD' (recover leakage coefficients in Macrolib);
*         'RHS' (recover leakage coefficients in RHS flux object);
*         'B0' (B-0), 'P0' (P-0), 'B1' (B-1),
*         'P1' (P-1), 'B0TR' (B-0 with transport correction) or 'P0TR'
*         (P-0 with transport correction).
* NUN     number of unknowns per energy group including spherical
*         harmonic terms, interface currents and fundamental
*         currents.
* MAXINR  maximum number of thermal iterations.
* EPSINR  thermal iterations epsilon.
* MAXOUT  maximum number of outer iterations.
* EPSUNK  outer iterations eigenvector epsilon.
* EPSOUT  outer iterations eigenvalue epsilon.
* IFRITR  number of free iterations in an acceleration cycle.
* IACITR  number of accelerated iterations in an acceleration cycle.
* ILEAK   method used to include DB2 effect:
*         =1 the scattering modified cp matrix is multiplied by PNLR;
*         =2 the reduced cp matrix is multiplied by PNL;
*         =3 sigs0-db2 approximation;
*         =4 albedo approximation;
*         =5 Todorova-type isotropic streaming model;
*         =6 Ecco-type isotropic streaming model;
*         >6 Tibere type anisotropic streaming model.
* NREG    number of regions.
* NSOUT   number of outer surfaces.
* MATCOD  mixture indices.
* KEYFLX  index of L-th order flux components in unknown vector.
* VOL     volumes.
* REFKEF  target effective multiplication factor (K-eff).
* NMERG   number of leakage zones.
* IMERG   leakage zone index in each material mixture zone.
*
*-----------------------------------------------------------------------
*
      USE GANLIB
*----
*  SUBROUTINE ARGUMENTS
*----
      CHARACTER   CXDOOR*12,TITLE*72,OPTION*4
      TYPE(C_PTR) IPFLUX,IPTRK,IPMACR,IPFLUP,IPSOU,IPSYS
      INTEGER     IPRT,IFTRAK,IPHASE,ITPIJ,INITFL,IREBAL,NGRP,NMAT,
     >            NIFIS,NANIS,NLF,NLIN,NFUNL,NUN,MAXINR,MAXOUT,
     >            IFRITR,IACITR,ILEAK,NREG,NSOUT,MATCOD(NREG),
     >            KEYFLX(NREG,NLIN,NFUNL),NMERG,IMERG(NMAT)
      REAL        EPSUNK,EPSINR,VOL(NREG)
      LOGICAL     LFORW,LEAKSW
      DOUBLE PRECISION REFKEF
*----
*  LOCAL VARIABLES
*----
      PARAMETER  (IUNOUT=6,NSTATE=40,NDIMO=2,ITYPEC=1)
      TYPE(C_PTR) JPMACR,KPMACR,JPFLUX,JPFLUP1,JPFLUP2,JPGPT,KPFLUX,
     1            KPGPT,JPSYS,KPSYS
      LOGICAL     LREBAL
      INTEGER     ISTATE(NSTATE)
      DOUBLE PRECISION AIL,BIL,GAZ
      REAL        EPSCON(5)
      CHARACTER   CAN(0:19)*2
*----
*  ALLOCATABLE ARRAYS
*----
      REAL, ALLOCATABLE, DIMENSION(:) :: SIGT,SIGS0
      REAL, ALLOCATABLE, DIMENSION(:,:) :: FLUXO,SOURO,XSTRC,XSTK
      REAL, ALLOCATABLE, DIMENSION(:,:,:) :: XSDIA,XSCHI,XSNUF
*----
*  DATA STATEMENTS
*----
      SAVE CAN
      DATA CAN /'00','01','02','03','04','05','06','07','08','09',
     >          '10','11','12','13','14','15','16','17','18','19'/
*----
*  SCRATCH STORAGE ALLOCATION
*----
      ALLOCATE(FLUXO(NUN,NGRP),SOURO(NUN,NGRP),XSTRC(0:NMAT,NGRP),
     > XSDIA(0:NMAT,0:NANIS,NGRP),XSCHI(0:NMAT,NIFIS,NGRP),
     > XSNUF(0:NMAT,NIFIS,NGRP),XSTK(NMAT,NIFIS))
*
      IF(IPRT.GE.3) THEN
        WRITE(IUNOUT,6000)
        WRITE(IUNOUT,6001) (IREGIO,VOL(IREGIO),MATCOD(IREGIO),
     >                      IREGIO=1,NREG)
      ENDIF
*----
*  RECOVER CROSS SECTIONS.
*----
      JPMACR=LCMGID(IPMACR,'GROUP')
      DO 100 IGR=1,NGRP
        KPMACR=LCMGIL(JPMACR,IGR)
        DO 10 IANI=0,NANIS
          CALL LCMLEN(KPMACR,'NJJS'//CAN(IANI),ILNLCM,ITYLCM)
          IF(ILNLCM.NE.NMAT) THEN
            CALL LCMLIB(KPMACR)
            CALL XABORT('FLUGPT: FLUX CALCULATION ERROR, SCATTERING'//
     >      ' MATRIX OF ORDER ANIS ='//CAN(IANI)//' NOT ON LCM')
          ENDIF
   10   CONTINUE
*----
*  RECOVER CORRECTED TOTAL AND WITHIN-GROUP SCATTERING CROSS SECTIONS
*----
        JPSYS=LCMGID(IPSYS,'GROUP')
        KPSYS=LCMGIL(JPSYS,IGR)
        CALL LCMLEN(KPSYS,'DRAGON-TXSC',ILCTX,ITYLCM)
        CALL LCMLEN(KPSYS,'DRAGON-S0XSC',ILCS0X,ITYLCM)
        IF(ILCTX.NE.NMAT+1) THEN
          CALL XABORT('FLUGPT: INVALID LENGTH FOR DRAGON-TXSC.')
        ELSE IF(MOD(ILCS0X,NMAT+1).NE.0) THEN
          CALL XABORT('FLUGPT: INVALID LENGTH FOR DRAGON-S0XSC.')
        ENDIF
        NANI_ASM=ILCS0X/(NMAT+1)-1
        ALLOCATE(SIGT(ILCTX),SIGS0(ILCS0X))
        SIGS0(:ILCS0X)=0.0
        CALL LCMGET(KPSYS,'DRAGON-TXSC',SIGT)
        CALL LCMGET(KPSYS,'DRAGON-S0XSC',SIGS0)
        XSTRC(0:NMAT,IGR)=SIGT(:NMAT+1)
        XSDIA(0:NMAT,0:NANIS,IGR)=0.0
        DO IANI=0,MIN(NANIS,NANI_ASM)
          DO IMAT=1,NMAT
            XSDIA(IMAT,IANI,IGR)=SIGS0(IANI*(NMAT+1)+IMAT+1)
          ENDDO
        ENDDO
        DEALLOCATE(SIGS0,SIGT)
        IF(IPRT.GE.3) THEN
          WRITE(IUNOUT,6002)  IGR
          WRITE(IUNOUT,6003) (IMAT,XSTRC(IMAT,IGR),
     >                             XSDIA(IMAT,0,IGR),IMAT=1,NMAT)
        ENDIF
*----
*  RECOVER FISSION CROSS SECTIONS
*----
        CALL LCMLEN(KPMACR,'CHI',ILONG,ITYLCM)
        IF( ILONG.EQ.0 )THEN
           CALL XABORT('FLUGPT: NO FISSION SPECTRA FOUND ON MACROLIB.')
        ELSE
           CALL LCMGET(KPMACR,'CHI',XSTK)
           DO 60 IFIS= 1, NIFIS
              XSCHI(0,IFIS,IGR)= 0.0
              DO 50 IMAT= 1, NMAT
                 XSCHI(IMAT,IFIS,IGR)= XSTK(IMAT,IFIS)
   50         CONTINUE
   60      CONTINUE
           CALL LCMGET(KPMACR,'NUSIGF',XSTK)
           DO 80 IFIS= 1, NIFIS
              XSNUF(0,IFIS,IGR)= 0.0
              DO 70 IMAT= 1, NMAT
                 XSNUF(IMAT,IFIS,IGR)= XSTK(IMAT,IFIS)
   70         CONTINUE
   80      CONTINUE
        ENDIF
        IF( IPRT.GT.3 )THEN
           WRITE(IUNOUT,6004) (IMAT,XSNUF(IMAT,1,IGR),
     >                              XSCHI(IMAT,1,IGR),IMAT=1,NMAT)
        ENDIF
        DO 90 IANI=0,NANIS
          CALL LCMLEN(KPMACR,'NJJS'//CAN(IANI),ILNLCM,ITYLCM)
        IF(ILNLCM.NE.NMAT) THEN
          CALL LCMLIB(KPMACR)
          CALL XABORT('FLUGPT: FLUX CALCULATION ERROR, '//
     >    'SCATTERING MATRIX OF ORDER ANIS ='//CAN(IANI)//' NOT ON LCM')
        ENDIF
   90   CONTINUE
  100 CONTINUE
*----
*  GPT FLUX INITIALIZATION
*----
      CALL LCMGET(IPSOU,'STATE-VECTOR',ISTATE)
      IF(LFORW) THEN
        CALL LCMLEN(IPFLUX,'DLUX',ILINIT,ITYLCM)
      ELSE
        CALL LCMLEN(IPFLUX,'ADFLUX',ILINIT,ITYLCM)
      ENDIF
      IF((ILINIT.EQ.0).OR.(INITFL.EQ.0)) THEN
        IF(LFORW) THEN
          MAXGPT=ISTATE(3)
          JPFLUX=LCMLID(IPFLUX,'DFLUX',MAXGPT)
        ELSE
          MAXGPT=ISTATE(4)
          JPFLUX=LCMLID(IPFLUX,'ADFLUX',MAXGPT)
        ENDIF
      ENDIF
*----
*  MAIN LOOP OVER EIGENVALUE FIXED SOURCE SOLUTIONS.
*----
      CALL LCMGET(IPFLUP,'STATE-VECTOR',ISTATE)
      IF(ISTATE(3).NE.11) CALL XABORT('FLUGPT: MISSING UNPERTURBED DIR'
     1 //'ECT AND/OR ADJOINT FLUXES.')
      JPFLUP1=LCMGID(IPFLUP,'FLUX')
      JPFLUP2=LCMGID(IPFLUP,'AFLUX')
      IF(LFORW) THEN
        JPGPT=LCMGID(IPSOU,'DSOUR')
      ELSE
        JPGPT=LCMGID(IPSOU,'ASOUR')
      ENDIF
      DO 1000 IGPT=1,MAXGPT
      CALL LCMLEL(JPGPT,IGPT,ILONG,ITYLCM)
      IF(ILONG.EQ.0) GO TO 1000
      IF(IPRT.GT.0) THEN
         WRITE(IUNOUT,'(1X,29(1H-)/25H FLUGPT: GPT EQUATION NB.,I5/
     1   1X,29(1H-))') IGPT
      ENDIF
      IF((ILINIT.EQ.0).OR.(INITFL.EQ.0)) THEN
        KPFLUX=LCMLIL(JPFLUX,IGPT,NGRP)
        DO 120 IGR=1,NGRP
          FLUXO(:NUN,IGR)=0.0
          DO 110 IREGIO=1,NREG
          IND=KEYFLX(IREGIO,1,1)
          IF(IND.GT.0) FLUXO(IND,IGR)=1.0
  110     CONTINUE
          IF(LFORW) THEN
            CALL LCMPDL(KPFLUX,IGR,NUN,2,FLUXO(1,IGR))
          ELSE
            CALL LCMPDL(KPFLUX,NGRP-IGR+1,NUN,2,FLUXO(1,IGR))
          ENDIF
  120   CONTINUE
      ENDIF
*----
*  RECOVER UNPERTURBED FLUXES AND VALIDATION OF THE FIXED SOURCE TERM.
*----
      IF(LFORW) THEN
        KPGPT=LCMGIL(JPGPT,IGPT)
        DO 130 IGR=1,NGRP
        CALL LCMGDL(JPFLUP2,IGR,FLUXO(1,IGR))
        CALL LCMGDL(KPGPT,IGR,SOURO(1,IGR))
  130   CONTINUE
      ELSE
        KPGPT=LCMGIL(JPGPT,IGPT)
        DO 140 IGR=1,NGRP
        CALL LCMGDL(JPFLUP1,IGR,FLUXO(1,IGR))
        CALL LCMGDL(KPGPT,IGR,SOURO(1,IGR))
  140   CONTINUE
      ENDIF
      AIL=0.0D0
      BIL=0.0D0
      DO 155 IGR=1,NGRP
      DO 150 IUN=1,NUN
      GAZ=FLUXO(IUN,IGR)*SOURO(IUN,IGR)
      AIL=AIL+GAZ
      BIL=BIL+GAZ**2
  150 CONTINUE
  155 CONTINUE
      IF(REAL(NUN)*SQRT(BIL).LT.EPSINR) GO TO 1000
      GAZ=ABS(AIL)/SQRT(REAL(NUN)*BIL)
      IF(GAZ.GT.EPSINR) CALL XABORT('FLUGPT: THE SOURCE TERM IS NOT OR'
     1 //'THOGONAL TO THE ADJOINT REFERENCE FLUX.')
*
      IF (CXDOOR.EQ.'MCCG') THEN
         CALL LCMLEN(IPTRK,'KEYCUR$MCCG',ICREB,ITYLCM)
         CALL LCMGET(IPTRK,'STATE-VECTOR',ISTATE)
         IF ((ICREB.GT.0).AND.(ISTATE(24).EQ.0)) THEN
            LREBAL=(IREBAL.EQ.1)
         ELSE
            LREBAL=(IREBAL.EQ.1).AND.(.NOT.LEAKSW)
         ENDIF
      ELSE
         LREBAL=(IREBAL.EQ.1).AND.(.NOT.LEAKSW)
      ENDIF
      CALL FLU2DR(IPRT,IPMACR,IPFLUX,IPSYS,IPTRK,IPFLUP,IPSOU,IGPT,
     1 IFTRAK,CXDOOR,TITLE,NUN,NREG,NSOUT,NANIS,NLF,NFUNL,NGRP,NMAT,
     2 NIFIS,LFORW,LEAKSW,MAXINR,EPSINR,MAXOUT,EPSUNK,EPSOUT,IFRITR,
     3 IACITR,ITYPEC,IPHASE,ITPIJ,ILEAK,OPTION,REFKEF,MATCOD,KEYFLX,
     4 VOL,XSTRC,XSDIA,XSNUF,XSCHI,LREBAL,INITFL,NMERG,IMERG)
 1000 CONTINUE
*----
*  END OF MAIN LOOP OVER EIGENVALUE FIXED SOURCE SOLUTIONS.
*----
      ISTATE(:NSTATE)=0
      ISTATE(1)=NGRP
      ISTATE(2)=NUN
      IF(LFORW) THEN
        ISTATE(3)=100
      ELSE
        ISTATE(3)=1000
      ENDIF
      ISTATE(4)=0
      ISTATE(5)=MAXGPT
      ISTATE(6)=ITYPEC
      ISTATE(7)=ILEAK
      ISTATE(8)=IFRITR
      ISTATE(9)=IACITR
      ISTATE(10)=IREBAL
      ISTATE(11)=MAXINR
      ISTATE(12)=MAXOUT
      ISTATE(17)=NMAT
      ISTATE(18)=NMERG
      CALL LCMPUT(IPFLUX,'STATE-VECTOR',NSTATE,1,ISTATE)
      EPSCON(1)=EPSINR
      EPSCON(2)=EPSUNK
      EPSCON(3)=EPSOUT
      EPSCON(4:5)=0.0
      CALL LCMPUT(IPFLUX,'EPS-CONVERGE',5,2,EPSCON)
      CALL LCMPTC(IPFLUX,'OPTION',4,OPTION)
*----
*  SCRATCH STORAGE DEALLOCATION
*----
      DEALLOCATE(XSTK,XSNUF,XSCHI,XSDIA,XSTRC,SOURO,FLUXO)
      RETURN
*----
*  FORMATS
*----
 6000 FORMAT(//30X,' EDITION REGION/VOL/MIXTURE '//
     >3(5X,'REGION',5X,'VOL  ',5X,'MIXTURE')/)
 6001 FORMAT(1P,3(5X,I4,4X,E12.5,4X,I4,4X))
 6002 FORMAT(//30X,' G R O U P : ',I5//
     >30X,' TOTAL MACROSCOPIC CROSS SECTIONS PER MIXTURE '/)
 6003 FORMAT(3(1X,'MIXTURE',4X,'NTOT0',11X,'SIGW',3X)/
     >1P,3(1X,I4,3X,E12.5,3X,E12.5))
 6004 FORMAT(3(1X,'MIXTURE',4X,'NUSIGF',11X,'CHI ',3X)/
     >1P,3(1X,I4,3X,E12.5,3X,E12.5))
      END