C ++********************************************************************
C                                                                      *
C STEP                                                                *
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 STEP(X,N,NV)
C
C PURPOSE:                                                                    *
C
C***********************************************************************

	SUBROUTINE  STEP(X,N,NV)

	DIMENSION  X(N)

	NV=0
	NC=N/2+1
	QS=STEPI(X,N,N,0)
	DO I=2,N
	   IF (I .LT. NC)  THEN
	      NN=I-1
	   ELSE
	      NN=N-I
	   ENDIF

           DO  J=1,NN
	      QT = STEPI(X,N,I,J)
	      IF (QT.LE.QS)  THEN
	         QS=QT
	         NU=I
	         NV=J
	      ENDIF
           ENDDO
	ENDDO

C	PRINT  555,NP,NU,NV,QS
C555	FORMAT(I3,5X,2I5,5X,F10.6)

        RETURN
	END