C ++********************************************************************
C                                                                      *
C                                                                      *
C                                                                      *
C **********************************************************************
C=* FROM: SPIDER - MODULAR IMAGE PROCESSING SYSTEM.   AUTHOR: J.FRANK  *
C=* Copyright (C) 1985-2005  Health Research Inc.                      *
C=*                                                                    *
C=* HEALTH RESEARCH INCORPORATED (HRI),                                *   
C=* ONE UNIVERSITY PLACE, RENSSELAER, NY 12144-3455.                   *
C=*                                                                    *
C=* Email:  spider@wadsworth.org                                       *
C=*                                                                    *
C=* This program is free software; you can redistribute it and/or      *
C=* modify it under the terms of the GNU General Public License as     *
C=* published by the Free Software Foundation; either version 2 of the *
C=* License, or (at your option) any later version.                    *
C=*                                                                    *
C=* This program is distributed in the hope that it will be useful,    *
C=* but WITHOUT ANY WARRANTY; without even the implied warranty of     *
C=* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  *
C=* General Public License for more details.                           *
C=*                                                                    *
C=* You should have received a copy of the GNU General Public License  *
C=* along with this program; if not, write to the                      *
C=* Free Software Foundation, Inc.,                                    *
C=* 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.      *
C=*                                                                    *
C **********************************************************************
C                                                                      *
C                                                                      *
C                                                                      *
C  PURPOSE:                                                            *
C                                                                      *
C  PARAMETERS:                                                         *
C                                                                      *
C        0         2         3         4         5         6         7 *
C23456789012345678901234567890123456789012345678901234567890123456789012
C***********************************************************************


	SUBROUTINE  PREPSL_s(NSAM,NSLICE,NN,NMAT,IPCUBE,RI)

	INTEGER  IPCUBE(5,*)
	LOGICAL  FIRST
	COMMON /PAR/  LDPX,LDPY,LDPZ,LDPNMX,LDPNMY

C
C IPCUBE: 1 - beginning
C         2 - end
C         3 - ix
C         4 - iy
C         5 - iz
C                   
	R=RI*RI
	NN=0
	NMAT=0
C
	DO    I1=1,NSLICE
	T=I1-LDPZ
	XX=T*T
	FIRST=.TRUE.
	DO    I3=1,NSAM
	NMAT=NMAT+1
	T=I3-LDPX
        RC=T*T+XX
	IF(FIRST)  THEN
	IF(RC-R)  80  ,80,14
80	FIRST=.FALSE.
	NN=NN+1
	IPCUBE(1,NN)=NMAT
	IPCUBE(2,NN)=NMAT
	IPCUBE(3,NN)=I3
	IPCUBE(4,NN)=1
	IPCUBE(5,NN)=I1	
	ELSE
	IF(RC.le.R)  IPCUBE(2,NN)=NMAT
	ENDIF
14	CONTINUE
	ENDDO
16	CONTINUE
20	CONTINUE
	ENDDO
	END